GB2062255A

GB2062255A - Weighing a Flowing Substance

Info

Publication number: GB2062255A
Application number: GB7936600A
Authority: GB
Original assignee: SP KONSTRUKT BJURO
Current assignee: SP KONSTRUKT BJURO
Priority date: 1979-10-22
Filing date: 1979-10-22
Publication date: 1981-05-20
Also published as: GB2062255B

Abstract

A flowing substance is directed into and out of a plurality of reservoirs 1 in a cyclic sequence so that unloading each reservoir is maintained coincident with loading another. Each reservoir is loaded during period tau 1 until the substance is present to within a predetermined upper range (Q3-Q4) then after a time interval tau 5 in which the substance can settle, the loaded reservoirs are weighed during interval tau 6 by dynamometric pickups 4 from which they are suspended. The reservoirs are unloaded during period tau 3 to within a predetermined lower range (Q1-Q2) and after a settling time tau 8 reweighed. Weighing data is memorised during periods tau 7 and tau 10 and relayed to arithmetic networks and a summation unit to provide indication of the total flow in a given time. The upper and lower ranges 25, 29 may be preset depending upon characteristics of the flow of substance, its weight, volume, loading or unloading time, or a combination thereof. <IMAGE>

Description

SPECIFICATION Method and Apparatus for Weight Determination of the Amount of a Flowing Substance The present invention relates to methods and apparatus for weight determination of the amount of a flowing substance, and more particularly but not exclusively to methods and apparatus for weight determination of the amount of continuously flowing substance.

The invention may be applicable to petrol, chemical and food industries, as well as to petroleum products supply, for precise quantative metering of liquid products, including receiving, pumping and dispensing operations performed at a given production rate. The term 'flowing substance' is used herein to imply a substance capable of fluid motion, though it is not limited to fluids and may for example comprise a stream of solid particles.

According to the invention there is provided a method of determining by weight the amount of flowing substance, the method comprising directing the flowing substance into and out of a plurality of reservoirs in a cyclic sequence so that unloading each reservoir is maintained coincident with loading another of the reservoirs, and in which each reservoir is loaded to within a predetermined upper range, weighed after a time interval, then unloaded to within a predetermined lower range and reweighed after another time interval, and the amount of substance is computed from the difference in the weighings.

The upper predetermined range depends on at least one of the substance volume, the substance weight and the loading time, and the lower predetermined ranged depends on at least one of substance volume, the substance weight and the unloading time.

If the flowing substance is a liquid it may be damped whilst it is in the reservoirs, in which case the flow of liquid may be introduced to and withdrawn from the reservoir at a level below its surface, and the weighing may be compensated for any additional hydrostatic component.

The invention also provides apparatus for determining by weight the amount of a flowing substance, the apparatus comprising a plurality of reservoirs suspended from dynamometric pickups which are rigidly fixed to a body, a control unit which is coupled to an inlet and an outlet of each reservoir and to an indicator which signals when the substance is present in any reservoir to within either predetermined upper or lower ranges, and a measuring unit, coupled to the control unit and each dynamometric pickup, which registers the weight of each reservoir with the substance present within the predetermined upper and lower ranges and relays data to a summation unit.Preferably the measuring unit comprises a plurality of arithmetic processing networks each of which has a data input coupled via a respective frequency converter to a respective one of the dynamometric pickups, two trigger inputs and their reset inputs coupled to outputs of the control unit and two control outputs coupled to corresponding inputs of the control unit and an output connected to the input of the summation unit. A time-mark generator with a plurality of outputs each coupled to a particular one of the arithmetic networks is provided.

The arithmetic processing networks comprise subtract binary counters, groups of AND gates equal in number to the bit positions of the counters and coupled to corresponding outputs thereof, first add binary counters having their inputs set by respective outputs of the AND gates, overlow acknowledgement circuits having their inputs coupled to complement outputs of high-order positions of the first add binary counters, controllable switches with inputs used for the data inputs, the trigger inputs the reset inputs, and the time-mark inputs of respective arithmetic processing networks, and outputs used for the control outputs and the data outputs of respective arithmetic processing networks and have further inputs coupled to the outputs of the overflow acknowledgement circuits, and have their respective outputs coupled to counting inputs of the subtract binary counter, to other inputs of respective AND gates, to counting inputs of the first add binary counters, to reset inputs of the subtract binary counters and the first add binary counters, the network also comprising second add binary counters having their counting and reset inputs coupled to respective outputs of the controllable switches and having their complement outputs of low- and high-order positions coupled to corresponding inputs of the controllable switches.

Bellows connecting with and disposed beneath the reservoirs may be provided for introducing and withdrawing the substance from the reservoirs. Each reservoir may be hermetically sealed and a second pair of bellows provided which connect with and are disposed above the reservoir to pass any volatile component of the substance.

Preferably the bellows and second pair of bellows are aligned and have identical cross-sections.

The reservoirs may be provided with dampers which rest on the surface of the substance. These dampers may comprise plates of smaller area than the cross-sectional area of its respective reservoir and which have an off-centre aperture through which an upright guide passes, the guide being fixed with relation to the reservoir.

A member may be provided to compensate for any hydrostatic component of the weight readings. The member may comprise a rod of greater length than the distance between the distal limits of the predetermined upper and lower ranges and which is disposed along the axis of symmetry of its reservoir and is aligned with and of the same cross-sectional area as the bellows.

The invention will now be described in more detail, by way of example, with reference to the accompanying drawings in which: Figure lisa timing diagram illustrating the variation of the amount of the substance during the operational cycle for each reservoir of an apparatus according to an embodiment of the invention; Figure 2 is a timing diagram illustrating the variation of the amount of the substance during the operational cycle of an embodiment of the invention which utilises three reservoirs; Figure 3 is a block diagram of an apparatus for carrying out the method of the invention; Figure 4 shows the construction of a reservoir in front view, partially sectioned, of a reservoir used in an embodiment of the invention; Figure 5 illustrates a network for arithmetic processing of the measured data which is suitable for use in the present invention;; Figure 6 is a block diagram of a controllable switch, which may be used in the arithmetic network; Figure 7 is a block diagram of an overflow acknowledgement circuit which may be used in the arithmetic processing network; Figure 8 is a block diagram of a control unit suitable for use in an embodiment of the invention; Figure 9 is a block diagram of a load control unit which may be used in the control unit of Figure 8; Figure 10 is a block diagram of a first unload control unit which may be used in the control unit of Figure 8; Figure 11 is a block diagram of second and third unload control units which may be used in the control unit of Figure 8; Figure 12 is a block diagram of a signal former to form trigger pulses for the arithmetic processing network incorporated in the control unit;; Figure 13 is a block diagram of a signal former to form signals to acknowledge that the substance level exceeds the preset limits of the preset ranges; Figure 14 is a block diagram of a time delay circuit of the control unit; Figure 1 5 is a block diagram of a time-mark generator; Figure 1 6 is a block diagram of a summation unit, and Figure 1 7 is a timing diagram illustrating the operation of the time-mark generator.

A method of determining, by weight the quantity of a continuously flowing substance is commenced by distributing the flow into a plurality of reservoirs, the continuity of flow being ensured, at any given time, by at least one of the reservoirs being filled. Once full each reservoir is weighed and then permitted to empty prior to refilling. The sequence of filling and emptying the reservoirs is maintained such that each reservoir is emptied simultaneously with another reservoir filling. Continuity of flow out of the reservoirs as well as into the reservoirs may be achieved with three or more reservoirs.

The operational cycle for each reservoir is shown in Figure 1, in which the repetition cycle occupies a time interval T, Time T1 is the duration for which the flow is directed into the reservoir, the loading ceasing when it is detected that the level within the reservoir is within a preset upper range Q3 to 04. During a subsequent time interval T2 the loaded reservoir is weighed, after which in time interval T3 it is unloaded, and then reweighed during time interval t4. Unloading is terminated when it is detected that the level in the reservoir has fallen to within a lower preset range Q1 to Q2' The time intervals T2 and T4 are each subdivided into, respectively T5, T6 and T8, T9 and Tao T5 and Ta are delay or 'setup' times during which the substance is allowed to settle or is damped in order to eliminate dynamic contributions to the weight readings, T6 and T9 are the periods when weighing takes place and T7 and T10 represent the times required for memorising the weights. The quantity of substance withdrawn from the reservoir is determined from the difference between the two weights, and this is also calculated during time interval T10 Summation of the difference values for all the reservoirs in a given time interval yields the total flow of the substance.After interval T10 the reservoir recommences loading again and the sequence is repeated.

The limits Q1, Q2 Q3 and Q4 of the lower and upper preset ranges are functionally related to characteristics of the flow and the substance. Basically Qa and Q4 correspond to the empty and full reservoirs and Q2 and 03 to values at which unloading and loading of the reservoirs should cease, and are determined by factors such as load and unload time, substance weight and substance volume or combinations thereof.Although the unloading and loading operations nominally cease at Q2 and Q3 inherent delays in the transport of the substance and in shutting of the inlet or outlet cause the actual level to lie between Q, to Q2 or Q3 to Q4 Use of preset upper and lower ranges to trigger shut off of the inlet or outlet enables variation in the characteristics of the flow to be accommodated, and in particular the use of the upper range eliminates overflow conditions.

The weight measuring apparatus and the reservoir capacity and weight, both when full and when empty, are chosen to be compatible so that the maximum weight of the reservoir and contents does not exceed the capability of the weighing apparatus, and likewise the weight of the unloaded reservoir is not below the minimum capability.

Identical reservoirs are used in one embodiment of the method of the invention in which case the time taken by each reservoir for the above described cycle of operations is the same, and the number of reservoirs which are required is determined from the relationships between time intervals Ta, T2, T3, and T4. The cycle of loading and unloading for each reservoir is delayed with respect to the cycle of another reservoir, so that within equal time intervals the input flow into the reservoirs equals the output flow and, therefore, continuity of flow is maintained. This sequence can be achieved for example by making the beginning of the loading of a reservoir considered to be a first one among the reservoirs simultaneous with the end of the loading of another of the reservoirs.Likewise in the unloading sequence the end of unloading one reservoir to within the preset lower range is made simultaneous with the beginning of unloading another reservoir, which commences at a level within the preset upper range.

Figure 2 shows the timing sequence for the flow of substance according to a method of the invention utilising three identical reservoirs. In this modification the loading interval T1 is equal to the unloading interval T3, and time intervals T2 and T4 which each include damping, weighing and memorising intervals, are equal and are each half as long as time intervals T1 and T3. The time periods for the full cycle of operations are respectively T1, T2 and T3 which are equal but progressively shifted in time by a time equal to T1 or T/3, so that as the first reservoir finishes loading the second commences, and as that reservoir finishes loading the third commences, and as that finishes loading the first recommences.Likewise the end of unloading one reservoir coincides with commencement of unloading the next in the 1, 2, 3, 1 etc cycle of the reservoir.

Different relationships between time intervals T, T2,T3 and T4 are possible in other modifications of the method of the invention, as well as differing number of reservoirs. In another modification two reservoirs can be used, in which case to maintain a continuous output the unload time interval T3 for each reservoir is equal to the sum of load time interval T1 and the time intervals T2, T4 i.e.

T3=Ta +T2+T4 A similar system catering for continuity of input would require: T=T3+T2+T4 If the flowing substance is a liquid it may be damped when it is in the reservoir, this may be achieved by a damper floating on the surface, or the liquid may be self-damped by the presence of a volume of liquid above the level of the inlet. In order to facilitate damping the inlet and outlet may both be situated at the bottom of the reservoir. Damping may introduce a weighing error due to a hydrostatic component: this error may be compensated by introduction of an equal opposing force, which may be effected by the liquid.

An apparatus in which the aforementioned method of weight determination may be carried out is illustrated schematically in Figure 3, and comprises three reservoirs 1,2 and 3, which are suspended respectively from dynamometric pickups 4, 5 and 6 which are mounted on a body 7. Reservoir loading means 8, 9, 10 and reservoir unloading means 11, 12, 13 which consist of shut off fittings with an electromagnetic drive, are coupled to inlet and outlet collectors 14, 1 5. Branch pipes 1 6, 1 7, 1 8 affixed respectively to the reservoir loading means 8, 9, 1 0, feed the substance into the reservoirs and flexible tubes 19, 20, 21, couple the reservoirs 1, 2, 3, with respective reservoir unloading means 11, 12, 13 for withdrawing the substance. The reservoirs 1, 2, 3 are provided with respective signalling means 22, 23, 24 to indicate that the level of the substance is within a preset upper range 25, and with signalling means 26, 27, 28 to indicate that the level of the substance is within a preset lower range 29. The preset upper range 25 corresponds to the end of loading each of the reservoirs 1 , 2, 3, while the preset lower range 29 corresponds to the end of unloading each of the reservoirs 1, 2, 3. Each of the signalling means 22, 23, 24, 25, 26, 27, 28 of the upper and lower ranges has its input coupled to a common chassis bus 30 of the apparatus.Frequency converters 31, 32, 33 are coupled to the dynamometric pickups 4, 5, 6, and each of the frequency converters 31, 32, 33 has its input coupled to the common chassis bus 30 of the apparatus. A control unit 34 has its inputs 35,36, 37 coupled, respectively, to the outputs of the signalling means 22, 23, 24 of the upper range and also has its inputs 38, 39, 40 coupled to the outputs of the signalling means 26, 27, 28 of the lower range.The control unit 34 has its outputs 41, 42, 43 coupled respectively, to the inputs of the electromagnets of the reservoir loading means 8, 9, 10, and also has its outputs 44, 45, 46 coupled, respectively, to the inputs of the electromagnets of the reservoir unloading means 11, 12, 13. A unit 47 measures and registers the amount of the substance, which unit includes three networks 48, 49, 50 for arithmetic processing of the measured data and determining the weight of the reservoirs 1, 2, 3 with the substance and the weighing results relating to the loaded and unloaded reservoirs 1, 2, 3, a time-mark generator 51, and a summation unit 52. The units 34, 48, 49, 50, 51, 52 have their respective inputs coupled to the common bus 30. The arithmetic processing networks 53, 54, 55 have their inputs 48, 49, 50 coupled to respective outputs of the frequency converters 31, 32, 33. Outputs 56, 57 of the arithmetic processing network 48, outputs 58, 59 of the arithmetic processing network 49, and outputs 60, 61 of the arithmetic processing network 50 are coupled, in pairs, to respective inputs of the of the control unit 34. Inputs 62, 63 of the arithmetic processing network 48, inputs 64, 65 of the arithmetic processing network 49, and inputs 66, 67 of the arithmetic processing network 50 are coupled, in pairs, to respective outputs of the control unit 34. Inputs 68 of the networks 48,49, 50 are joined together and coupled to a respective output of the control unit 34.Outputs 69, 70, 71 of the networks 48, 49, 50, respectively, are coupled to corresponding inputs of the summation unit 52. The remaining input of the summation unit 52 is coupled to the inputs 68 of the networks 48, 49, 50.

Inputs 72, 73, 74 of the networks 48, 49, 50 are coupled to respective outputs of the time-mark generator 51. A supply unit 75 has an output coupled to the common bus 30. An output 76 of said unit 75 is coupled to respective inputs of the frequency converters 31, 32, 33, whereas an output 77 is coupled to the inputs of the electromagnets (not shown) of the reservoir loading means 8, 9, 10 and reservoir unloading means 11, 12, 13. An output 78 of said unit 75 is coupled to respective inputs of the control unit 34, networks 48,49, 50 of the time-mark generator 51, and summation unit 52.

The reservoirs 1, 2, 3 are affixed with rods 79 (Fig. 4) to suspensions 80 resting on respective dynamometric pickups 4, 5, 6, which are mounted on top of the body 7.

To provide for simpler construction and increased accuracy of weighing the reservoirs 1, 2, 3 with the substance, bellows 82 are attached with flanges 81 on external end face members of the reservoirs and have their lower portions fixed to T-pieces 84 with flanges 83. The bellows 82 serve concurrently as the substance feeding means 16, 1 7, 1 8 and the substance withdrawal means 1 9, 20, 21 of Figure 3.

The reservoir loading means 8, 9, 10 are connected with the reservoir unloading means 11, 1 2, 13 by means of the T-pieces 84 secured on the lower part of the body 7. The reservoir loading means 8, 9, 10 are connected with the inlet collector 14, while the reservoir unloading means are connected with the outlet collector 15.

To avoid the loss of volatile components of the substance, which could otherwise contaminate the surroundings, the reservoirs 1, 2, 3 are hermetically sealed. For this purpose, bellows 86 are fixed to their upper end face portions and have their upper portions connected with a flange 87 to chambers 88, which are rigidly mounted on top of the body 7. The bellows 86 are installed in coaxial relation to the bellows 82, the cross-sections of the bellows 86, 82 being equal to each other. Branch pipes 89 coupled with the chamber 88 are used to pass the volatile components of the substance, which are led into them from the reservoirs 1, 2, 3 via the bellows 86.

To reduce the error of weighing the reservoirs 1, 2, 3 with the liquid, in case they are loaded and unloaded from under the liquid surface, rods 90 are located within the reservoirs along their axes of symmetry to compensate for the hydrostatic components of the weight of the liquid, said rods 90 being rigidly mounted on the chambers 88. The rods 90 have their lengths exceeding the distance between the upper limit of the preset upper range 25 and the lower limit of the preset lower range 29 and have their upper end faces positioned above the upper limit of the preset upper range 25. The bellows 82, 86 and the rod 90 are arranged in a coaxial relation and have equal cross-sections, which are uniform through their entire lengths.

Affixed with their ends to the interior of the upper end face members of the reservoirs 1, 2, 3 are tubes 91 of magnetically permeable material. The tubes 91 accommodate the signaliing means 22, 23, 24 for the preset upper range and the signalling means 26, 27, 28 for the preset lower range. The signalling means 22, 23, 24, 25, 26, 27, 28 are hermetically sealed magnet-controlled contact subassemblies.

To decrease the dynamic components of the load on the dynamometric pickups 4, 5, 6 which occurs during loading and unloading the reservoirs 1, 2, 3 and to increase the production rate of the apparatus with the accuracy of weighing maintained at higher level, liquid damping means are adapted to rest on the liquid surface within the reservoirs 1, 2, 3 which means are floats in the form of plates 92 having each two holes for the rods 90 and tubes 91, the diameters of these holes being greater than the diameters of the rods 90 and tubes 91. Mounted on the plates 92, close to the holes for the tubes 91 are magnets 93 which interact with the signalling means 22,23,24 and the signalling means 26, 27, 28.

To describe the arithmetic processing networks 48, 49, 50 (Fig. 5), the network 48 is taken as an example. The latter comprises a subtract binary counter 94 having its outputs coupled, in a bit-bybit manner, to respective inputs of two-input AND gates 95. The outputs of the AND gates 95 are coupled, in a bit-by-bit manner, to set inputs of an add binary counter 96. The number of the bit positions of the add binary counter 96 and the subtract binary counter 94 as well as the number of the AND gates 95 of each of the networks 48, 49, 50 is determined by the requirement to be met by the accuracy of determining the weight of the reservoirs 1, 2, 3 with the substance. The complement output of the high-order position of the add binary counter 96 is coupled to the input of an overflow acknowledgement circuit 97. Each of the networks 48,49, 50 comprises a controllable switch 98 whose output 99 is coupled to a counting input of the subtract binary counter 94. The controllable switch 98 has an output 100 coupled to the second inputs of the AND gates 95, an output 101 coupled to a counting input of the add binary counter 96, an output 1 02 coupled to reset inputs of the bit positions of the subtract binary counter 94, of the add binary counter 96, and of an add binary counter 103, an output 104 coupled to a counting input of the add binary counter 103, an input 105 coupled to the output of the overflow acknowledgement circuit 97, and also outputs 106,107 coupled to the complement outputs of the low- and high-order positions of the add binary counter 103.An input of the controllable switch 98 of the network 48 is used as an input 53 of that network. A second input of the controllable switch 98 of the network 48 is used as an input 62 of the network 48. A third input of the controllable switch 98 of the network 48 is an input 63 of the network 48. A fourth input of the controllable switch 98 of the network 48 is an input 68 of the network 48. A fifth input of the controllable switch 98 of the network 48 is an input 72 of the network. An input of the controllable switch 98 of the network 48 is an output 56 of the network. A second output of the controllable switch 98 of the network 48 is an output 57 of the network. A third output of the controllable switch 98 of the network 48 is an output 69 of the network. An input of the controllable switch 98 of the network 49 is an input 54 of the network.A second input of the controllable switch 98 of the network 49 is an input 64 of the network. A third input of the controllable switch 49 is an input 65 of the network. A fourth input of the controllable switch 49 is an input 68 of the network. A fifth input of the controllable switch 98 of the network 49 is an input 73 of the network. An output of the controllable switch 98 of the network 49 is an output 58 of the network. A second output of the controllable switch 98 of the network 49 is an output 59 of the network. A third output of the controllable switch 98 of the network 49 is an output 70 of the network. An input of the controllable switch 98 of the network 50 is an input 55 of the network. A second input of the controllable switch 98 of the network 50 is an input 66 of the network. A third input of the controllable switch 98 of the network 50 is an input 67 of the network.A fourth input of the controllable switch 98 of the network 50 is an input 68 of the network. A fifth input of the controllable switch 98 of the network 50 is an input 74 of the network 50. An output of the controllable switch 98 of the network 50 is an output 60 of the network 50. A second output of the controllable switch 98 of the network 50 is an output 61 of the network 50. A third output of the controllable switch 98 of the network 50 is an output 71 of the network.

Every controllable switch 98 comprises flip-flops 1 08, 109, 110, 111, 11 2, 113 (Fig. 6), two inputAND-NOTgates 114,115,116, 117,two-inputORgates 118,119,120,121,122, 123,124, three-input AND-NOT gates 125, 126, two inverters 127, 128, and an overflow acknowledgement circuit 129.

The set input of the flip-flop 109 is an input 106 of the controllable switch 98. An input of the AND-NOT gate 114 is, respectively, input 53, 54, 55 (Fig. 3) of the networks 48, 49, 50.

The input of the overflow acknowledgement circuit 129 (Fig. 6) is an input 107 of the controllable switch 98. An input of the OR gate 11 8, coupled to an input of the OR gate 1 20 is, respectively, the input 62, 64, 66 (Fig. 3) of the networks 48, 49, 50. Another input of the OR gate 11 8 (Fig. 6), coupled to the set input of the flip-flop 111 and to an input of the OR gate 1 23, is, respectively, the input 63, 65, 67 (Fig. 3) of the networks 48, 49, 50. An input of the OR gate 11 9 (Fig. 6), coupled to an input of the OR gates 120, 121, 122, 123, to the output of the inverter 127, and to the output of the overflow acknowledgement circuit 129, is the input 68 (Fig. 3) of the networks 48, 49, 50. An input of the AND-NOT gate 117 (Fig. 6), coupled to respective input of AND-NOT gates 125, 126 is, respectively, the input 72, 73, 74 (Fig. 3) of the networks 48, 49, 50. An input of the AND gate 122 (Fig. 6), coupled to the set input of the flip-flop 11 2, is the input 105 of the controllable switch 98. The output of the AND-NOT gate 114 is the output 1 04 of the controllable switch 98.The output of the AND-NOT gate 125 is the output 99 of the controllable switch 98. The output of the inverter 128 is the output 100 of the controllable switch 98. The output of the OR gate 124 is the output 101 of the controllable switch 98. The output of the OR gate 122, coupled to the reset inputs of the flip-flops 11 0, 111, is the output 1 02 of the controllable switch 98. The true output of the flip-fiop 11 3 is, respectively, the output 56, 58, 60 (Fig. 3) of the networks 48, 49, 50. The output of the AND-NOT gate 117 (Fig. 6), coupled to an input of the OR gate 124 is, respectively, the output 69, 70, 71 (Fig. 3) of the networks 48, 49, 50.

The true output of the flip-flop 11 2 (Fig. 6) of the controllable switch 98 of the network 48 is the output 57 (Fig. 3) of the network. The complement outputs of the flip-flops 11 2 of the controllable switches 98 of the networks 49, 50 are, respectively, the outputs 59, 61 of the networks. The set input of the flip-flop 108 (Fig. 6) is coupled to the output of the OR gate 11 8, while the reset input of the flipflop 108 is coupled to the output of the OR gate 119. The true output of the flip-flop 1 08 is coupled to an input of the AND-NOT gate 114. An input of the OR gate 11 9, coupled to the input of the inverter 1 27 and to an input of the OR gate 121, is connected to the output of the overflow acknowledgement circuit 129.The output of the OR gate 120 is coupled to the reset input of the flip-flop 112. The output of the OR gate 121 is coupled to the reset input of the flip-flop 109. The true output of the flip-flop 109 is coupled to respective inputs of the AND-NOT gates 125, 1 26. The output of the inverter 1 27 is coupled to respective inputs of the AND-NOT gates 11 5, 11 6. The output of the AND-NOT gate 11 5 is coupled to the set input of the flip-flop 11 0. The true output of the flip-flop 110 is coupled to an input of the AND-NOT gate 117. The true output of the flip-flop 111 is coupled to an input of the AND-NOT gate 11 5 and to an input of the AND-NOT gate 126. The true output of the flip-flop 111 is coupled to an input of the AND-NOT gate 11 6 and to an input of the AND-NOT gate 125. The output of the AND NOT gate 11 6 is coupled to the input of the inverter 128 and to the set input of the flip-flop 113. The reset input of the flip-flop 113 is coupled to the output of the OR gate 1 23. The output of the AND-NOT gate 126 is coupled to an input of the OR gate 124.

To describe the overflow acknowledgement circuits 97 (Fig. 5) and the overflow acknowledgement circuits 129 (Fig. 6), the circuit 97 is taken as an example. The latter comprises an inverter 130 (Fig. 7), whose output is coupled to an input of a two-input AND-NOT gate 131, a diode 1 32 having its cathode coupled to another input of the AND-NOT gate 131 and used as the output of the circuit 97. The circuit 97 also comprises a capacitor 133 having one lead coupled to the common bus 30 and having another lead coupled to the input of the inverter 130, which is coupled to the anode of the diode 132 and to a lead of a resistor 1 34. The other lead of the resistor 1 34 is coupled to a logic 1 potential. The output of the AND-NOT gate 131 is the output of the overflow acknowledgement circuit 97.

The control unit 34 comprises load control units 135,136,137 (Fig. 8) to control loading the reservoirs 1, 2, 3, respectively, an unload control unit 138 to control unloading the reservoir 1, unload control units 139, 140 to control unloading the reservoirs 2, 3, signal formers 141, 142, 143 to produce signals acknowledging that the substance level exceeds the preset upper range, signal formers 144, 145, 146 to produce signals acknowledging that the substance level exceeds the preset lower range, signal formers 147, 148, 149 to produce trigger signals for triggering the networks 48, 49, 50, and beginning-of-measurement delay circuits 1 50, 1 51, 152. An input 1 53 of the load control unit 135 is coupled to the output of a two-input AND-NOT gate 1 54. An input 155 of the load control unit 135 is coupled to an input of two-input OR gate 156, to an input of a three-input OR gate 157, to an input 1 58 of the load control unit 137, to inputs 1 59, 1 60 of the signal formers 142, 143, to an input 161 of the signal former 149, said input 155 being used as the input 37 of the control unit 34. An input 1 62 of the load control unit 1 35 is coupled to the output 57 (Fig. 3) of the network 48.An input 163 (Fig. 8) of the load control unit 135 is coupled to an input of the AND-NOT gate 1 54, to the input of an inverter 164, to an input of a four-input OR gate 165, to an input 1 66 of the load control unit 136, to inputs 167,168 of respective signal formers 141, 143, to an input 1 69 of the signal former 147, said input 1 63 being used as the input 35 of the control unit 34. An input 1 64 of the load control unit is coupled to inputs 171, 172 of the load control units 136, 137, to inputs 173,174,175 of the unload control units 138, 139, 140, to inputs 1 76, 177, 1 78 of the signal formers 147, 148, 149, and to the true output of a flip-flop 179.An input 180 of the unload control unit 138 is coupled to the output of a three-input AND-NOT gate 1 81. An input 1 82 of the unload control unit 1 38 is coupled to an output of a three-input of the AND-NOT gate 1 83. An input 1 84 of the unload control unit 138 is coupled to respective inputs of the AND-NOT gates 183, to an input of the OR gate 1 65, to inputs 1 85, 186 of the signal formers 144, 146, to the input of the inverter 187, to an input 188 of the signal former 147, said input 184 being used as the input 38 of the control unit 34. An output 1 89 of the load control unit 135 is used as the output 41 of the control unit 34. An output 1 90 of the unload control unit 138 is the output 44 of the control unit 34. An output 1 91 of the unload control unit 138 is coupled to an input of a two-input AND-NOT gate 1 92.An output 193 of the unload control unit 138 is coupled to an input 194 of the load control unit 135. An input 1 95 of the load control unit 136 is coupled to an input of the OR gate 165 and to the output of the AND-NOT gate 196. An input 197 of the load control unit 1 36 is coupled to the output of a two-input NOR gate 1 98. An input 199 of the load control unit 136 is coupled to an input 200 of the load control unit 1 37, to an input of a threeinput OR gate 201, to inputs 202, 203 of the signal formers 141, 142, to an input 204 of the signal former 148, said input 199 being used as the input 36 of the control unit 34. An input 205 of the unload control unit 139 is coupled to the output of the inverter 1 87. An input 206 of the unload control unit 139 is coupled to the output 58 (Fig. 3) of the network 49.An input 207 (Fig. 8) of the unload control unit 139 is coupled to an input of a three-input OR gate 201, to the input of an inverter 208, to inputs 209, 210 of the signal formers 144, 145, to an input 211 of the signal former 148, said input 207 being used as the input 39 of the control unit 34. An output 212 of the load control unit 136 is the output 42 of the control unit 34. An output 213 of the unload control unit 139 is the output 45 of the control unit 34. An output 214 of the unload control unit 1 39 is coupled to an input of a two-input AND-NOT gate 215. An output 216 of the unload control unit 139 is coupled to an input 217 of the load control unit 136.An input 218 of the load control unit 137 is coupled to a lead of a resistor 219, to an input of a two-input AND-NOT gate 220, and to a logic 1 potential. An input 221 of the load control unit 137 is coupled to the output of a two-input NOR gate 222. An input 223 of the unload control unit 140 is coupled to the output of inverter 208. An input 224 of the unload control unit 140 is coupled to the output 60 (Fig. 3) of the network 50. An input 225 (Fig. 8) of the unload control unit 140 is coupled to the input of an inverter 226, to inputs 227, 228 of the signal formers 145, 146, to an input 229 of the signal former 149, to an input of the OR gate 1 57, said input 225 being used as the input 40 of the control unit 34. An output 230 of the load control unit 1 37 is the output 43 of the control unit 34. An output 231 of the unload control unit 140 is the output 46 of the control unit 34.

An output 232 of the unload control unit 140 is coupled to an input of a two-input AND-NOT gate 233.

An output 234 of the unload control unit is coupled to an input 235 of the load control unit 137. An input 236 of the signal former 141 is coupled to inputs 237, 238, 239, 240, 241 of corresponding signal formers 142, 143, 144, 145, 146, to the output of a two-input OR gate 242, and to the inputs 68 (Fig. 3) of the networks 48, 49, 50. An input of a three-input AND-NOT gate 181 (Fig. 8), coupled to an input of a three-input OR gate 1 83, is coupled to the output 56 (Fig. 3) of the network 48. An input of a two-input NOR gate 1 98 (Fig. 8), to the output 59 (Fig. 3) of the network 49.An input of a twoinput NOR gate 222 (Fig. 8) is coupled to the output 61 (Fig. 3) of the network 50. An input 243 (Fig.

8) of the delay circuit 1 50 is coupled to the output of a four-input OR gate 1 65. An output 244 of the delay circuit 1 50 is coupled to an input 245 of the signal former 147 of the network 48 are coupled, respectively, to the inputs 62, 63 (Fig. 3) of that network. An input 248 (Fig. 8) of the delay circuit 1 51 is coupled to the output of a three-input OR gate 201. An output 249 of the delay circuit 151 is coupled to an input 250 of the signal former 148. Outputs 251, 252 of the signal former 148 are coupled, respectively, to the inputs 64, 65 (Fig. 3) of that network. An output 249 of the delay circuit 151 is coupled to an input 250 of the signal former 148. Outputs 251, 252 of the signal former 148 are coupled, respectively, to the inputs 64, 65 (Fig. 3) of the network 49.An input 253 (Fig. 8) of the delay circuit 1 52 is coupled to the output of a three-input OR gate 1 57. An output 254 of the delay circuit 1 52 is coupled to an input 255 of the signal former 149. Outputs 256, 257 of the signal former 149 are coupled, respectively, to the inputs 66, 67 (Fig. 3) of the network 50. Outputs 258, 259, 260 (Fig. 8) of the signal formers 141, 142, 143 are coupled to respective inputs of a three-input OR gate 261 whose output is coupled to an input of a four-input OR gate 262. Outputs 263, 264, 265 of the signal formers 144, 145, 146 are coupled to respective inputs of a three-input OR gate 266 whose output is coupled to an input of a four-input OR gate 262.The set input of the flip-flop 179 is coupled to the set input of a flip-flop 267, to the input of an inverter 268, to an input of the OR gate 242, and to a lead of a "Start" button 269 of the apparatus, which has another lead coupled to a respective lead of a "Stop" button 260 of the apparatus and to the common bus 30. Another lead of the "Stop" button 270 is coupled to an input of the OR gate 262 whose output is coupled to the reset input of the flipflop 1 79. An input of the OR gate 262 is coupled to respective inputs of the OR gates 1 56, 242 and to the output of the AND-NOT gate 220. An input of the AND-NOT gate 220 is coupled to the output of an inverter 271 whose input is coupled to respective leads of resistors 219,272 and to a lead of a capacitor 272. The other leads of the resistor 272 and the capacitor 273 are coupled to the common bus 30.The complement output of the flip-fiop 1 79 is coupled to respective inputs of the AND-NOT gates 192, 21 5, 233. An input of the OR gate 165 is coupled to the output of the AND-NOT gate 192.

An input of the OR gate 201 is coupled to the output of the AND-NOT gate 21 5. An input of the OR gate 1 57 is coupled to the output of the AND-NOT gate 233. An input of the AND-NOT gate 1 81 is coupled to the true output of the flip-flop 267. An input of the AND-NOT gate 1 83 is coupled to the output of the inverter 226. An input of the OR gate 1 98, coupled to an input of the NOR gate 222, is connected to the complement output of the flip-flop 267 whose reset input is coupled to the output of the OR gate 1 56. An input of the AND-NOT gate 154, coupled to an input of the AND-NOT gate 1 96, is connected to the output of the inverter 268. The other input of the AND-NOT gate 1 96 is coupled to the output of the inverter 1 64.

To describe the load control units 135, 136, 137 (Fig. 9) for respective reservoirs 1, 2, 3, consider the unit 135. The latter comprises an inverter 274 whose output is coupled to an input of a four-input AND-NOT gate 275. An input of a two-input OR gate 276 is coupled to the output of a four-input AND NOT gate 275, while the output of the OR gate 276 is coupled to the set input of a flip-flop 278. The output of a two-input OR gate 277 is coupled to the reset input of the flip-flop 278 and to an input of the AND-NOT gate 275. A resistor 279 has a lead coupled to the true output of the flip-flop 278 and has another lead coupled to the base lead of a transistor 280 whose emitter lead is coupled to the common bus 30.Respective inputs of two-input OR gates 276 of the units 135,136,137 are the inputs 153,195,218 of these units. The inputs of the inverters 274 of the units 135,136,137 are, respectively, the inputs 1 55, 1 66, 200 of these units. Corresponding inputs of the AND-NOT gates 275 of the units 135,136,137 are, respectively, the inputs 162,197,221 of these units. The other inputs of the AND-NOT gates 275 of the units 135, 136, 137 are, respectively, the inputs 194, 217, 235 of these units.Respective inputs of the OR gates 277 of the units 135, 136, 137 are, correspondingly, the inputs 1 63, 1 99, 1 58 of these units, while the other inputs of the OR gates 277 are, respectively, the inputs 170, 171, 172 of these units. The collector leads of the transistors 280 of the units 135, 136, 137 are, respectively, the outputs 1 89, 212, 230 of these units.

The unload control unit 138 for the reservior 1 comprises two-input OR gates 281, 282 (Fig. 10) whose outputs are coupled, respectively, to the set and reset inputs of a flip-flop 283. The unit 1 38 also comprises a resistor 284 having one lead coupled to the true output of the flip-flop 283, and having another lead coupled to the base lead of a transistor 285 whose emitter lead is coupled to the common bus 30. An input of the OR gate 281 is the input 180 of the unit 138, while the other input of the OR gate 281 is the input 182 of the unit 138. An input of the OR gate 282 of the unit 138 is the input 1 73 of the unit, and the other input of the OR gate 282 is the input 1 84 of the unit. The true output of the flip-flop 283 of the unit 138 is the output 1 91 of the unit, while the complement output of the flip-flop 283 is the output 1 93 of the unit 138. The collector lead of the transistor 285 of the unit 1 38 is the output 1 90 of that unit.

To describe the unload control units 1 39, 140 (Fig. 11) for the reservoirs 2, 3, respectively, the unit 139 is taken as an example. The latter comprises a two-input AND-NOT gate 286 and a two-input OR gate 287 whose outputs are coupled, respectively, to the set and reset inputs of a flip-flop 288. A resistor 289 has a lead coupled to the true output of the flip-flop 288, and has another lead coupled to the base lead of a transistor 290 whose emitter lead is coupled to the common bus 30.Corresponding inputs of the AND-NOT gates 286 of the units 139, 140 are, respectively, the inputs 205, 223 of the units 139, 140. The other inputs of the AND-NOT gates 286 are, respectively, the inputs 206, 224 of the units 139, 140. Corresponding inputs of the OR gates 287 are, respectively, the inputs 174,175 of the units 139, 140. The other inputs of the AND-NOT gates 287 are, respectively, the inputs 207,225 of the units 139, 140. The true outputs of the flip-flops 288 of the units 139, 140 are, respectively, the outputs 214, 232 of these units.The complement outputs of the flip-flops 288 are, respectively, the outputs 216,234 of the units 139, 140. The collector leads of the transistors 290 of the units 139, 140 are, respectively, the outputs 213, 231 of the units 139, 140.

To describe the signal formers 147, 148, 149 (Fig. 12) for producing trigger pulses for the networks 48, 49, 50, respectively, the signal former 147 is taken as an example. The latter comprises a two-input OR gate 291 whose output is coupled to the input of the inverter 292. Corresponding inputs of two-inputs AND-NOT gates 293, 294 are coupled to the output of an inverter 295, while the other inputs of the AND-NOT gates 293, 294 are coupled, respectively, to the output of an inverter 296 and to the output of the inverter 292. The inputs of the inverters 296 of the signal formers 147,148,149 are, respectively, the inputs 1 69, 204, 1 61 of these signal formers.The inputs of the inverters 295 of the signal formers 147, 148, 149 are, respectively, the inputs 245,250,255 of these signal formers.

Corresponding inputs of the OR gates 291 of the signal formers 147, 148, 149 are, respectively, the inputs 176, 177, 1 78 of these signal formers, while the other inputs of the OR gates 291 are, respectively, the inputs 1 88, 211 229 of these signal formers. The outputs of the AND-NOT gates 293 of the signal formers 147, 148, 149 are, respectively, the outputs 246, 251,256 of the units 147, 148, 149, and the outputs of the AND-NOT gates 294 are, respectively, the outputs 247,252,257 of these units.

The signal formers 141, 142, 143, 144, 145, 146 (Fig. 13) for producing signals acknowledging that the substance level exceeds the prescribed limits in the reservoirs 1, 2, 3, respectively, are described using an example of the signal former 141. The latter comprises a flip-flop 295 whose counting input is coupled to the output of an inverter 296 whose reset input is coupled to the output of a two-input OR gate 297 and to an input of a three-input AND-NOT gate 298. The complement output of the flip-flop 295 is coupled to the cathode of a diode 299 and to an input of a three-input AND-NOT gate 298. An inverter 300 has its input coupled to the cathode of the diode 299 and to a lead of a capacitor 301, and also has its output coupled to an input of the AND-NOT gate 298.The other lead of the capacitor 301 is coupled to the common bus 30. The inputs of the inverters 296 of the signal formers 141,142,143,144,145,146 are, respectively, the inputs 167,203,160, 185,210,228 of these signal formers. The OR gates 297 of the signals formers 141, 142, 143, 144, 145, 146 have their corresponding inputs used as the inputs 202, 1 59, 1 68, 209, 227, 1 86 of these signal formers, respectively, and also have their other inputs used, respectively, as the inputs 236, 237, 238, 239, 240, 241 of these signal formers. The AND-NOT gates 298 of the signal formers 141, 142, 143, 144, 145, 146 have their outputs used, respectively, as the outputs 258, 259, 260, 263, 264, 265 of these signal formers.

The delay circuits 150, 1 51, 1 52 (Fig. 14) are described using the circuit 150 as an example. The latter comprises a two-input AND-NOT gate 302 whose output is coupled to the cathode of a diode 303 and to an input of a two-input AND-NOT gate 304 which has another input coupled to the output of an inverter 305. The input of the inverter 305 is coupled to the anode of the diode 303 and to respective leads of a resistor 306 and a capacitor 307. The other lead of the capacitor 307 is coupled to the common bus 30, while the other lead of the resistor 306 is coupled to a logic 1 potential.The delay circuit 1 50 comprises an inverter 308 whose input is coupled to the anode of a diode 309 and to respective leads of a resistor 310 and a capacitor 311, and whose output is coupled to a respective input of a two-input AND-NOT gate 312 which has the other input coupled to the cathode of the diode 309, to the output of the AND-NOT gate 304, and to an input of the AND-NOT gate 302.

Corresponding leads of the resistor 310 and the capacitor 311 are coupled, respectively, to a logic 1 potential and to the common bus 30. Respective inputs of the AND-NOT gates 302 of the delay circuits 150, 1 51, 1 52 are, correspondingly, the inputs 243, 248, 253 of these circuits. The outputs of the AND-NOT gates 312 of the delay circuits 150, 151, 152 are, respectively, the outputs 244, 249, 254 of these circuits.

The time-mark generator 51 (Fig. 1 5) of the substance measuring/registering unit 47 comprises a crystal-controlled oscillator 313 having its output coupled to the cathode of a diode 314 and to an input of a two-input AND-NOT gate 315 which has the other input coupled to the output of an inverter 316. The input of the inverter 31 6 is coupled to the anode of the diode 314 and to a lead of a capacitor 317 which has the other lead coupled to the common bus 30. The time-mark generator also comprises an inverter 318 whose input is coupled to the anode of a diode 319 and to a lead of a capacitor 320 which has the other lead coupled to the common bus 30. The cathode of the diode 319 is coupled to the output of the AND-NOT gate 315, to the cathode of a diode 321 and to the input 72 (Fig. 3) of the network 48. The anode of the diode 321 (Fig. 15) is coupled to an input of a two-input AND-NOT network 322 and to a lead of a capacitor 325. The other lead of the capacitor 325 is coupled to the common bus 30, while the other input of the AND-NOT gate 322 is coupled to the output of the inverter 318. The output of the AND-NOT gate 322 is coupled to the cathodes of the diodes 324, 325 and to the input 73 (Fig. 3) of the network 49. The anode of the diode 324 (Fig. 1 5) is coupled to a lead of a capacitor 326 and to the input of the inverter 327 whose output is coupled to an input of a twoinput AND-NOT gate 328. The other input of the AND-NOT gate 328 is coupled to the anode of the diode 325 and to a lead of a capacitor 329. The other leads of the capacitors 326, 329 are coupled to the common bus 30.The output of the AND-NOT gates 328 is coupled to the input 74 (Fig. 3) of the network 50.

The summation unit 52 (Fig. 1 6) comprises an add binary-decade counter 330 having its counting input coupled to the output of a three-input OR gate 331, and also having its outputs connected, in a bit-by-bit manner, to respective inputs of a measurement results indicating circuit 332 and a measuring results registering circuit 333. The inputs of the OR gate 331 are coupled to the outputs 69, 70, 71 (Fig. 3) of corresponding networks 48, 49, 50 while the reset input of the counter 330 (Fig. 1 6) is coupled to the inputs 68 (Fig. 3) of the networks 48, 49, 50.

The apparatus of the invention operates in the following manner. When the apparatus supply unit 75 (Fig. 3) is energized, the capacitor 273 (Fig. 8), which has been discharged using the circuit of the resistor 272, begins to charge using the current whose value is determined by the rated value of the resistor 21 9. The value of the resistor 272 is 30 to 100 times the value of the resistor 21 9. In this case, logic 1 is present at the output of the inverter 271 until the capacitor 273 is given a voltage at which the inverter 271 operates. At the point in time when the capacitor 273 assumes a voltage at which the inverter 271 operates, the output of the latter produces logic 0.The output of the AND-NOT gate 220 produces a pulse whose length corresponds to the charge time of the capacitor 273 with which the operating voltage of the inverter 271 is reached. That pulse is applied, via the OR gates 262,156 to the reset inputs of the flip-flops 179,267 so that these inputs are brought to 0.At the same time, the above-mentioned pulse passes through the OR gate 242 and is applied to the inputs 236, 237, 238, 239, 240, 241 of the signal formers 141, 142, 143, 144, 145, 146, to the inputs 68 of the networks 48, 49, 50, and to a particular input of the summation unit 52, which is coupled to the inputs 68 of the networks 48, 49, 50. Logic 0 obtainable from the true output of the flip-flop 179 (Fig. 8) at the inputs 170, 1 71, 172 of the load control units 135, 136, 137 brings the flip-flops 278 (Fig. 9), via the OR gates 277, to 0.

In this case, the transistors 280 of the units 135, 136, 137 are held non-conductive, the electromagnets of the reservoir loading means 8, 9, 1 0 (Fig. 3) are de-energized and the means 8, 9, 10 are therefore closed.

Logic 0 applied to the inputs 173, 1 74, 1 75 of the unload control units 138, 139, 140 from the true output of the flip-flop 1 79 (Fig. 8) brings the flip-flop 283 (Fig. 10) of the unload control unit 1 38 of the reservoir 1 and the flip-flops 288 (Fig. 11) of the unload control units 1 39, 140 of the reservoirs 2, 3 to 0. In this case, the transistor 285 (Fig. 10) of the unit 138 and the transistors 290 (Fig. 11) of the units 139, 140 are held non-conductive, the electromagnets of the reservoir unloading means 11, 1 2, 1 3 (Fig. 3) are de-energized, and the means 11, 12, 1 3 are therefore closed.With the abovementioned operations performed, the apparatus automatically assumes the initial state. To activate the apparatus, it is necessary to depress the "Start" button 269 (Fig. 8) of the control unit 34. With the button 269 depressed, the flip-flops 179,267 take up the 1 state. Logic 1 is applied, from the true output of the flip-flop 179, to the inputs 170, 171, 172, 173, 1 74, 175 of the load control units 135, 136, 137 and the unload control units 1 38, 1 39, 1 40, respectively. Logic 1, from the true output of the flip-flop 267, is applied to a respective input of the AND-NOT gate 181. Depressing the button 269 results in a formation, at the output of the OR gate 242, of a pulse whose length corresponds to the time within which the button 269 is held depressed.That pulse is applied to the inputs 68 (Fig. 3) of the networks 48, 49, 50 and to an input of the summation unit 52, coupled to the inputs 68 of the networks 48, 49, 50. In addition, for the time interval corresponding to the depressed condition of the button 269 (Fig. 8), logic 1 is present at the output of the inverter 268, with the result that the AND NOT gates 1 96, 1 54 are made conducting. Thereafter, the output of one of the AND-NOT gates 1 96, 154 produces a pulse applied to either the input 195 of the load control unit 136 or the input 153 of the load control unit 135.The appearance of that pulse at the output of one of the AND-NOT gates 1 96, 1 54 depends on the substance level in the reservoir 1 (Fig. 3). With the reservoir 1 filled to the fullest extent (the substance level is positioned within the limits of the preset upper range 25), the input 35 of the control unit 34 is given logic 0 from the output of the signalling means 22. The output of the inverter 1 64 (Fig. 8) produces in this case logic 1 with which the AND-NOT gate 196 is made conductive while the AND-NOT gate 1 54 is not conducting. A trigger pulse is applied to the input 1 95 of the load control unit 136 of the reservoir 2. That pulse passes through the OR gates 276 (Fig. 9) of the unit 136 and is applied to the set input of the flip-flop 278 so that the latter takes up the 1 state.

The transistor 280 is made conductive, with the result that the electromagnet of the reservoir loading means 9 is switched on. Thus, the latter is open and the substance begins to fill the reservoir 2. At the same time, the above-mentioned pulse is applied, from the output of the AND-NOT gate 196 (Fig. 8), to a respective input of the OR gate 1 65 and then to the input 243 of the delay circuit 1 50, with the result that the latter is activated. After a delay time relating to the beginning of measuring the weight of the reservoir 1 (Fig. 3) filled with the substance has elapsed, the output 244 (Fig. 8) of the delay circuit 1 50 produces a pulse applied to the input 245 of the signal former 147.That pulse passes via the inverter 295 (Fig. 12) and is applied to respective inputs of the AND-NOT gates 293, 294 The AND NOT gate 294 is held non-conductive using logic 0 obtainable from the output of the inverter 292.

Since logic 1 's appear at the inputs 1 76, 1 88 (Fig. 8) of the signal former 147, no trigger pulse can pass via the AND-NOT gate 294 (Fig. 12). The AND-NOT gate 293 is made conducting under the action of logic 1 obtainable from the output of the inverter 296. There is logic 0 at the input of the inverter 296, available from the output of the signalling means 22 (Fig. 3). As a result, the signal from the output of the inverter 295 (Fig. 12) passes through the AND-NOT gate 293 and is then applied to the input 62 (Fig. 3) of the network 48, which is activated.On completion of the cycle of measuring the weight of the reservoir 1 with the substance, the output 56 of the network 48 produces logic 1 which is applied to respective inputs of the AND-NOT gates 181, 183 (Fig. 8) of the control unit 34. That logic 1 passes through the AND-NOT gate 181 and is inverted therein, so that logic 0 is applied to the input 180 of the unload control unit 138. As a result, logic 0 appears at the output of the OR gate 281 (Fig.

10), and the flip-flop 283 assumes the 1 state.

The transistor 285 is made conducting and the electromagnet of the reservoir unload means 1 2 (Fig. 3) is activated. Thus, the means 12 is open and the loading of the reservoir 1 commences. In most cases, however, the apparatus, when activated by depressing the button 269 (Fig. 8), operates with the reservoir 1 not filled with the substance to the fullest extent. In this case, logic 1 appears at the input 35 (Fig. 8) of the control unit 34, so that the AND-NOT gate 154 is made conducting and the AND-NOT gate 1 96 stops conducting. With the button 269 depressed, the apparatus trigger pulse passes through the AND-NOT gate 1 54 to the input 1 53 of the load control unit 1 35.That pulse passes through the OR gate 276 (Fig. 9) and the flip-flop 278 takes up the 1 state. The transistor 280 is made conducting and the electromagnet of the reservoir loading means 8 (Fig. 3) is energized to open the latter. As a result, the loading of the reservoir 1 is effected. After it is complete (the substance level is maintained between the upper and lower limits of the preset upper range 25), the signalling means 22 operates and the input 35 of the control unit 34 produces logic 0. The latter is applied to the input 1 63 (Fig. 8) of the load control unit 1 35, passes through the OR gate 277 (Fig. 9) and the flip-flop 278 takes up the 0 state.The transistor 280 is made non-conductive, the electromagnet of the reservoir loading means 8 (Fig. 3) is de-energized, and the flow of the substance to the reservoir 1 is stopped. At the same time, logic 0 from the input 35 of the control unit 34 is applied to the input 1 66 (Fig. 8) of the load control unit 136 and passes through the inverter 274 (Fig. 9) and the AND-NOT gate 275, so that the flip-flop 278 takes up the 1 state. The transistor 280 is made conductive and the electromagnet of the reservoir loading means 9 (Fig. 3) is energized. The means 9 is open and the loading of the reservoir 2 commences.The same signal from the input 35 of the control unit 34 passes through the OR gate 165 (Fig. 8) to the input 243 of the delay circuit 1 50 and the latter is activated. After a time interval necessary for the reservoir loading means 8 (Fig. 3) to be closed and the reservoir 1 with the substance to be settled, the output 244 (Fig. 8) of the delay circuit 150 produces a pulse applied to the input 245 of the signal former 147. That pulse passes through the inverter 295 (Fig. 12) and through the AND NOT gate 293 is applied to the input 62 (Fig. 3) of the network 48 and the latter is thus activated.On completion of the cycle of measuring the weight of the reservoir 1 with the substance, the output 56 of the network 48 produces logic 1 which passes through the AND-NOT gate 181 (Fig. 8) and is inverted therein and is then applied to the input 180 of the unload control unit 138. Thereafter, that signal passes through the OR gate 281 (Fig. 10) to the set input of the flip-flop 283 and the latter assumes the 1 state. The transistor 285 is made conducting and the electromagnet of the reservoir unloading means 11 (Fig. 3) is energized. The means 11 is open and the unloading of the reservoir 1 is effected.

When the substance in the reservoir 2 being loaded reaches the preset upper range 25, the signalling means 23 operates and the input 38 of the control unit 34 produces logic 0. The latter is applied to input 1 99 (Fig. 8) of the load control unit 136, passes through the OR gate 277 (Fig. 9) and the flip-flop 278 therefore takes up the 0 state. The transistor 280 is made non-conductive and the electromagnet of the reservoir loading means 9 (Fig. 3) is de-energized. The means 9 is closed and the loading of the reservoir 2 is stopped.At the same time, logic 0 is applied, from the input 36 of the control unit 34, to the input 200 (Fig. 8) of the load control unit 137 and passes through the inverter 274 (Fig. 9) and AND-NOT gate 275 to bring the flip-flop 278 to the 1 state. The transistor 280 is made conductive and the electromagnet of the reservoir loading means 10 (Fig. 3) is energized. The means 10 is made open and the loading of the reservoir 3 is effected. The same signal from the input 36 of the control unit 34 is applied to a respective input of the OR gate 201 (Fig. 8) and then passes to the input 248 of the delay circuit 151 so that it is activated.

After a delay time necessary for the beginning of measurement has elapsed, the output 249 of the delay circuit 151 produces a pulse applied to the input 250 of the signal former 148. That pulse passes through the inverter 295 (Fig. 12) and the AND-NOT gate 293 and is applied to the input 64 (Fig. 3) of the network 49 so that the cycle of measuring the reservoir 2 with the substance commences.

On completion of the cycle of measuring the reservoir 2 with the substance, the output 58 of the network 49 produces logic 1 applied to the input 206 (Fig. 8) of the unload control unit 139. When the substance level in the reservoir 1 (Fig. 3) being unloaded reaches the preset lower range 29, the signalling means 26 operates and logic 0 appears at the input 38 of the control unit 34 and then passes to the input 1 84 (Fig. 8) of the unload control unit 1 38. Thereafter, that signal passes through the OR gate 282 (Fig. 10), brings the flip-flop 283 to the 0 state and makes the transistor 285 nonconductive.The electromagnet of the reservoir unloading means 11 (Fig. 3) is de-energized, the means 11 is closed and the flow of the substance from the reservoir 1 is stopped. That signal passes from the signalling means 26 through the inverter 1 87 (Fig. 8) to the input 205 of the unload control unit 139 and then passes through the AND-NOT gate 286 (Fig. 11) to the set input of the flip-flop 288 which assumes the 1 state. The transistor 290 is made conducting and the electromagnet of the reservoir unloading means 12 (Fig. 3) is switched over so that the latter is open and the unloading of the reservoir 2 is effected.At the same time, the above-mentioned signal passes through the OR gate 165 (Fig. 8) to the input 243 of the delay circuit 1 50 with the result that the latter is activated. After a delay time for the beginning of measurement has elapsed, the output 244 of the delay circuit produces a pulse applied to the input 245 of the signal former 147. This signal passes through the inverter 295 (Fig. 12) and the AND-NOT gate 294 (with the AND-NOT gate 293 maintained in this case in the nonconductive state) and is applied to the input 63 (Fig. 3) of the network 48 which is therefore activated.

On completion of the cycle of measuring the weight of the reservoir 1 unloaded and determining the weight of the substance withdrawn from that reservoir, the result is registered in the summation unit 52 and logic 1 appears at the output 57 of the network 48. That signal is applied to the input 1 62 (Fig.

8) of the load control unit 135.

When the substance level in the reservoir 3 (Fig. 3) being loaded reaches the preset upper range 25, the signalling means 24 operates and signal is applied to the input 37 of the control unit 34. This signal is applied to the input 1 58 (Fig. 8) of the load control unit 1 37. Thereafter, the signal passes through the OR gate 277 (Fig. 9) and brings the flip-flop 278 to the 0 state. The transistor 280 is made conducting and the electromagnet of the reservoir loading means 10 (Fig. 3) is de-energized. The means 10 is closed and the flow of the substance to the reservoir 3 is stopped. The same signal passes through the OR gate 156 (Fig. 8) and the flip-flop 267 takes up the 0 state.The AND-NOT gate 181 is made non-conductive using logic 0 from the true output of the flip-flop 267, applied to a respective input of that gate, whereas logic 0's appear at the outputs of the NOR gates 1 98, 222, with the result that the reservoir loading means 9, 10 (Fig. 3) are held closed till the moment the networks 49, 50 work out respective enable signals. These enable signals are applied, from the outputs 59, 61 of the networks 49, 50 to respective inputs of the NOR gates 1 98, 222 (Fig. 8) of the control unit 34. The signal from the output of the signalling means 24 (Fig. 3) is applied to the input 37 of the unit 34 and passes to the input 1 55 (Fig. 8) of the load control unit 135.As stated above, the reservoir loading means 8 is made open and the flow of the substance is admitted into the reservoir 1. Moreover, the signal passes through the OR gate 1 57 (Fig. 8) to the input 253 of the delay circuit 1 52 and the latter is therefore activated. After a delay time for the beginning of measurement has elapsed, the output 254 of the delay circuit 1 52 produces a pulse which is applied to the input 255 of the signal former 149 and passes through the inverter 295 (Fig. 12) and the AND-NOT gate 293 and then appears at the input 66 (Fig. 3) of the network 50 so that it is activated.On completion of the cycle of measuring the weight of the reservoir 3 with the substance, the output 60 of the network 50 produces logic 1 applied to the input 224 (Fig. 8) of the unload control unit 140. After a certain time interval has elapsed, the unloading of the reservoir 2 (Fig. 3) down to the preset lower range 29 is complete. The signalling means 27 operates and the input 39 of the control unit 34 produces logic 0 applied to the input 207 (Fig. 8) of the unload control unit 1 39 and passes through the OR gate 287 (Fig. 11) with the result that the flip-flop 288 takes up the 0 state. The transistor 290 is not conducting and the electromagnet of the reservoir unloading means 12 (Fig. 3) is de-energized.The means 12 is closed and no flow of the substance is withdrawn from the reservoir 2. The same signal from the output of the signalling means 27 is applied, through the inverter 208 (Fig. 8), to the input 223 of the unload control unit 140. The signal passes through the AND-NOT gate 286 (Fig. 11), with the result that the flip-flop 288 takes up the 1 state. Thus, the electromagnet of the reservoir unloading means 13 (Fig. 3) is energized and the unloading of the reservoir 3 is effected. The same signal also passes through the OR gate 201 (Fig. 8) to the input 248 of the delay circuit 151 so that it is activated.After a time interval necessary for the reservoir unloading means 12 to be closed and the reservoir 2 with the remaining portion of the substance therein to settle, the output of the delay circuit 1 51 (Fig. 8) produces a signal applied to the input 250 of the signal former 1 48. Thereafter, the signal passes through the inverter 295 (Fig. 12) of the unit 148 and the AND-NOT gate 294 (the AND-NOT gate 148 is not conducting in this case) and is then applied to the input 65 (Fig. 3) of the network 49 so that it is activated.On completion of the cycle of measuring the weight of the unloaded reservoir 2 with the remaining portion of the substance and registering the result in the summation unit 52, the output 59 of the network 49 produces logic 0 applied to a respective input of the NOR gate 1 98 (Fig. 8) of the control unit 34 and then to the input 1 97 of the load control unit 136. The reservoir 1 is loaded in a manner that the substance reaches the preset upper range 25 before the reservoir 3 (Fig. 3) is unloaded. This is acknowledged by the signalling means 22 whose output produces a signal applied to the input 35 of the control unit 34. As stated above, this results in closure of the reservoir loading means 8, in opening the reservoir loading means 9, and in measuring the weight of the reservoir 1 with the substance after a time interval determined by a delay of the beginning of measurement, provided by the delay circuit 150 (Fig. 8). At the following point in time, the unloading of the reservoir 3 (Fig. 3) is terminated. The signalling means 28 operates and logic 0 appears at the input 40 of the control unit 34. That signal is applied to the input 225 (Fig. 8) of the unload control unit 140 and passes through the OR gate 287 (Fig. 11) and through the flip-flop 288 which takes up the 0 state.The transistor 290 is not conducting and the electromagnet of the reservoir unloading means 13 (Fig. 3) is de-energized so that the latter is closed and the flow of the substance from the reservoir 3 is stopped.

At the same time, that signal is applied, via the inverter 226 (Fig. 8) and the AND-NOT gate 183, to the input 182 of the unload control unit 138, so that the reservoir unloading means 11 (Fig. 3) is open and the reservoir 1 is unloaded. The same signal is applied, via the OR gate 1 57 (Fig. 8), to the input 253 of the delay circuit 1 52 which is therefore activated. After a time interval for delay of the beginning of measurement has elapsed, the output 254 of the delay circuit 1 52 produces a signal applied to the input 255 of the signal former 149. That signal passes through the inverter 295 (Fig. 12) and the AND-NOT gate 294 and is applied to the input 67 (Fig. 3) of the network 50 with the result that the latter is activated.On completion of the cycle of weighing the unloaded reservoir 3, determining the weight of the substance withdrawn from it, and registering the result in the summation unit, the output 61 of the network 50 produces logic 0. The latter passes through the NOR gate 222 (Fig. 8) and is applied to the input 221 of the load control unit 137. Thereafter, the apparatus performs the operations in accordance with the above sequence till the moment when the flip-flop 1 79 (Fig. 8) of the control unit 34 takes up logic 0.This event can occur under the following conditions: the supply unit 75 (Fig. 3) is energized; the button 270 (Fig. 8) of the control unit 34 is depressed; a signal is available from one of the signal formers 141, 142, 143, 144, 145, 146. The signals pass from the outputs 258, 259, 260 of the signal formers 141, 142, 143, via the OR gate 261, to a respective input of the OR gate 262. The signals from the outputs 263, 264, 265 of the signal formers 144, 145, 146 pass through the OR gate 266 to the reset input of the flip-flop 179.

The first case relating to the energization of the supply unit 75 (Fig. 3) has been described above.

When the button 270 (Fig. 8) of the control unit 34 is depressed, the sequence of the operations of the apparatus is as follows. The flip-flop 1 79 takes up the 0 state and logic 1 from its complement output is applied to respective inputs of the AND-NOT gates 1 92, 21 5, 233 having their corresponding inputs coupled to the inputs 191,214,232 of the unload control units 138, 139, 140. Prior to depressing the button 270, logic 1 appears at the output of one of the units 138, 139, 1 40 and logic 0 appears at the outputs of the remaining units. Under these conditions, one of the reservoirs 1, 2, 3 is unloaded.A short pulse is generated at the output of one of the AND-NOT circuits 192,215,233 which is applied to the input of one of the delay circuits 150, 1 51, 1 52 and the circuit is thus activated.

Thereafter, logic 0 from the true output of the flip-flop 179 is applied to the inputs 1 70, 171, 1 72, 173, 174,175 of the load control units 135, 136, 137 and the unload control units 138, 139, 140.

respectively. This results in the closure of the reservoir loading means 8, 9, 1 0 (Fig. 3) and the reservoir unloading means 11, 12, 13.

After a time interval for delay of the beginning of measurement has elapsed, the output of one of the delay circuits 150, 151, 152 (Fig. 2), which has been activated by the pulse from one of the AND NOT gates 1 92, 21 5, 233, produces a signal applied to the input of one of the signal formers 147, 148, 149. That signal passes through the inverter 295 (Fig. 12) and the AND-NOT gate 294 and is applied to one of the inputs 63,65,67 (Fig. 3) of their respective networks 48,49, 50, with the result that a particular network is activated.On completion of the cycle of measuring the weight of the reservoir being handled for unloading at the moment when the button 270 (Fig. 8) is depressed, and of determining the weight of the unloaded reservoir with the substance, the result is registered in the summation unit 52 (Fig. 3), and the apparatus is stopped until the button 269 (Fig. 8) of the control unit 34 is depressed.

The sequence of operations in the third case as stated above will be described using the signal former 141.

With the button 269 depressed, the signal from the output of the OR gate 242 is applied to the input 236 of the signal former 141 and passes through the OR gate 297 (Fig. 13) and brings the flipflop 295 to the 0 state. When the signal from the signalling means 22 (Fig. 3) arrives at the input 167 (Fig. 8) of the signal former 141 , the output of the inverter 296 (Fig. 13) produces a positive pulse with which the flip-flop 295 is brought to the 1 state. If the substance level in the reservoir 1 (Fig. 3) continues to rise and reaches the upper limit of the preset upper range 25, the signalling means 22 operates again.The signal is applied to the input 167 (Fig. 8) of the signal former 141 and passes through the inverter 296 (Fig. 1 3) so as to bring the flip-flop 295 to the 0 state. In this case, logic 1 applied to the cathode of the diode 299 makes that diode non-conductive. The capacitor 301 begins to charge using the input current of the inverter 300. As the capacitor 301 charges to the operating voltage of the inverter 300, logic 1's appear at the inputs of the AND-NOT gate 298 (one of the inputs of the gate is connected to the output of the OR gate 297 and is thus given logic 1 too), whereas the output of the AND-NOT gate 298 produces a short pulse applied, via the OR gate 261 (Fig. 8), to the reset input of the flip-flop 1 79 of the control unit 34. Further operation of the apparatus is the same as in the case of depressing the button 270 of the control unit 34.

Like the delay circuits 1 51, 1 52, the delay circuit 1 50 operates in the following manner. When a trigger pulse is applied to the input 243 of the delay circuit 1 50 the univibrator of that circuits, built around the AND-NOT gates 302, 304 (Fig. 14), inverter 305, capacitor 307, resistor 306, and diode 303, takes up the 0 state. Obtainable from the output of the AND-NOT gate 304, logic 0 is applied to the cathode of the diode 309 of the delay circuit 1 50 and makes the latter conducting. The capacitor 311 discharges via the diode 309. When the voltage across the capacitor 307 reaches the operating value for the inverter 305, the output of the AND-NOT gate 304 takes up the 1 state.Logic 1 brings the diode 309 to the non-conductive state and the capacitor 311 begins to charge via the resistor 310 until its voltage reaches the operating value for the inverter 308. The output of the AND-NOT gate 312, which is the output of the delay circuit 1 50, produces a short pulse whose length is equal to the charge time of the capacitor 311 within which it is given a voltage equal to the operating one of the inverter 308. The time interval between the moment of triggering the delay circuit 1 50 and the moment when the pulse is formed at its output 244 is the delay time for the beginning of measuring the reservoir, which delay time is determined by the charge time of the capacitor 307 within which the voltage across it reaches the operating voltage for the inverter 305.

The arithmetic processing networks 48, 49, 50 (Fig. 3) provide the means for converting data on the weight of the reservoirs 1, 2, 3 with the substance, available from the frequency converters 31, 32, 33 in the form of rectangular pulses, into a unitary code proportional to the difference between the weights of the loaded and unloaded reservoirs 1, 2, 3. The unitary codes obtainable from the data outputs 69, 70, 71 of the networks 48, 49, 50 are summed up and, if necessary, are registered in the summation unit 52.

The operation of the networks 48, 49, 50 (Fig. 3) is described using the network 48 as an example. When a reset pulse is applied, from the output of the control unit 34, to the input 68 of the network 48 via the OR gate 11 9 (Fig. 6) of the controllable switch 98 of the network 48 (Fig. 5), the flip-flop 108 (Fig. 6) takes up the 0 state. The same pulse passes via the OR gate 120 so that the flipflop 112 assumes the 0 state. In addition, the same pulse passes through the OR gates 121, 123 to bring the flip-flops 109, 11 3 to the 0 state.That pulse also passes through the OR gate 1 22 to bring the flip-flops 110, 111, and also the subtract binary counter 94 (Fig. 5), the add binary counter 96, and the add binary counter 103 of the network 48, to the 0 state. The beginning-of-measurement signal applied, from the output of the control unit 34 (Fig. 3), to the input 62 of the network 48 passes through the OR gate 11 8 (Fig. 6) and brings the flip-flop 108 to the 1 state.Logic 1 from the true output of the flip-flop 108 is applied to a respective input of the AND-NOT gate 114 and the latter is made conducting to pass the pulses from the frequency converter 31 (Fig. 3) which carry data on the weight of the reservoir 1 with the substance and appears at the counting input of the add binary counter 103 (Fig. 5) of the network 48. On the arrival of a first, as counted since the moment at which the AND-NOT gate 114 (Fig. 6) is made conducting, negative edge of a pulse from the output of the frequency converter 31, the complement output of the low-order position of the add binary counter 103 (Fig. 5) produces logic 0 applied to the set input of the flip-flop 109 (Fig. 6) with the result that the latter takes up the 1 state.Logic 1 from the true output of the flip-flop 109 is applied to a respective input of the AND-NOT gate 125 which is thus made conducting. The r.f. pulses from the time-mark generator 51 (Fig. 3) pass through the AND-NOT gate 125 (Fig. 6) to the counting input of the subtract binary counter 94 (Fig. 5). In the case of overflow of the add binary counter 103, the complement output of its high-order position produces logic 1 applied to the input of the overflow acknowledgement circuit 129 (Fig. 6). The output of the circuit 129 then produces a short pulse which passes through the OR gate 121 to cause the flip-flop 129 to assume the 0 state. Logic O is applied to the input of the AND-NOT gate 1 25 and the latter is therefore not conducting.As a result, no r.f. pulses are applied to the counting input of the subtract binary counter 94 (Fig. 5). The number of r.f. pulses applied is given by N=n . T1 . f (1) where n is the number of the bit positions of the add binary counter 103 of the arithmetic processing network 48; T, is the repetition rate of the pulses of the frequency converter 31 (Fig. 3), representative of the weight of the reservoir 1 filled with the substance: f is the frequency of the r.f. pulses of the time-mark generator 51.

The following codeword is placed in the subtract binary counter 34 (Fig. 5): K=2K~ N (2) where K is the number of the bit positions of the subtract binary counter 94.

The pulse from the output of the overflow acknowledgement circuit 129 (Fig. 6) passes through the inverter 127 and through the AND-NOT gate 116 (with the AND-NOT gate 11 5 not conducting in this case) and the flip-flop 113 assumes the 1 state. The pulse also passes through the inverter 1 28 to cause the AND-NOT gates 95 (Fig. 5) to conduct. The codeword contained in the subtract binary counter 94 is placed into the add binary counter 96. At this step, the cycle of measuring the weight of the reservoir 1 (Fig. 3) with the substance is complete.

When the beginning-of-measurement pulse from the output of the control unit 34 is applied to the input 63 of the network 48, it then passes through the OR gate 11 8 (Fig. 6) and causes the flip-flop 108 to take up the 1 state. The same pulse causes the flip-flop 111 to take up the 1 state and, on passing the OR gate 123, it also causes the flip-flop 113 to take up the 0 state. Logic 1 from the true output of the flip-flop 1 08 is applied to a respective input of the AND-NOT gate 11 4 and causes it to conduct.The rectangular pulses from the output of the frequency converter 31 (Fig. 3) carrying data on the weight of the reservoir 1 which is unloaded at the given point in time pass through the AND-NOT gate 114 (Fig. 6) to the counting input of the add binary counter 103 (Fig. 5). On the arrival of a first, as counted since the moment at which the AND-NOT gate 114 (Fig. 6) is made conducting, negative edge of a pulse from the output of the frequency converter 31 (Fig. 3), the complement output of the loworder add binary counter 103 (Fig. 5) produces logic 0. The latter causes the flip-flop 109 (Fig. 6) to take up the 1 state.The r.f. pulses from the output of the time-mark generator 51 (Fig. 3) pass through the AND-NOT gates 126 (Fig. 6), with the AND-NOT gates 125, 126 made non-conductive using logic 0 obtained from the complement output of the flip-flop 111, and through the OR gate 124 to the counting input of the add binary counter 96 (Fig. 5). In the case of overflow of the add binary counter 103, the complement output of the high-order position produces logic 1. The output of the overflow acknowledgement circuit 129 (Fig. 6) produces a short pulse which cause the flopflop 109 to take up the 0 state. That pulse passes through the inverter 127 and the AND-NOT gate 115 and causes the flip-flop 110 to take up the 1 state.The AND-NOT gate 126 is made non-conductive using logic 0 applied to its respective input from the true output of the flip-flop 110. The r.f. pulses pass through the AND-NOT gate 11 7 and the OR gate 1 24 from a respective output of the time-mark generator 51 (Fig. 3) to the counting input of the add binary counter 96 (Fig. 5) and are also applied, from the output of the AND-NOT gate 11 7 (Fig. 6) to a respective input of the summation unit 52 (Fig. 3). In the case of overflow of the add binary counter 96 (Fig. 5), the complement output of the high-order position produces logic 1 applied to the input of the overflow acknowledgement circuit 97.The output of the latter produces a short pulse which causes the flip-flop 112 (Fig. 6) to take up the 1 state. That pulse also passes through the OR gate 122 and causes the flipflops 110, 111 to take up the 0 state and the subtract binary counter 94 (Fig. 5), the add binary counter 96 and the add binary counter 103 to reset. At this step, the cycle of measuring the weight of the reservoir 1 (Fig. 3) unloaded, determining the weight of the substance withdrawn from it and summing the result with data previously stored in the summation unit 52.

The number of r.f. pulses applied from the output 69 of the network 48 to respective input of the summation unit 52 is given by: N=N1 -N2 (3) where N, is the number of r.f. pulses, representative of the weight of the reservoir 1 loaded; N2 is the number of r.f. pulses, representative of the weight of the reservoir 1 unloaded.

N2=n. T2.f (4) where n is the number of bit positions of the add binary counter 103 (Fig. 5) of the network 48; T2 is the repetition rate of the pulses of the frequency converter 31 (Fig. 3), representative of the weight of the reservoir 1 unloaded; fis the frequency of r.f. pulses of the time-mark generator.

Thus: N=N1-N2=n. T, . fn2 . T2. f=n . f(TT2)=K. AT (5) AT is the repetition rate difference for the pulses of the frequency converter 31, representative of the weight of the substance withdrawn from the reservoir 1; K is the coefficient determined by a multiple proportion between the number N, and the weight of the reservoir 1 with the substance.

The overflow acknowledgement circuits 97 (Fig. 5) of the networks 48, 49, 50 and the overflow acknowledgement circuits 129 (Fig. 6) of the controllable switches 98 operate in a similar manner described below. When logic 1 is applied to the input of the circuit 97, diode 132 (Fig. 7) is not conducting and the capacitor 133 begins to charge via the resistor 134. Prior to that point in time, the capacitor 133 discharged via the diode 132. During the charge time of the capacitor 1 33 in which it is given a voltage equal to the operating voltage of the inverter 97, logic 1's are present at the inputs of the AND-NOT gates 131. Logic O is present at the AND-NOT gate 131.When the voltage across the capacitor 133 reaches the value of the operating voltage of the inverter 1 30, the output of the latter produces logic 0. In this case, the output of the AND-NOT gate 1 37 produces logic 1. Therefore, the appearance of logic 1 at the input of the circuit 97 results in the formation at its output of a short pulse whose length corresponds to the charge time of the capacitor 133 within which it is given a voltage equal to the operating voltage of the flip-flop 1 30.

The time-mark generator 51 (Fig. 3) designed to form three synchronous trains of frequencystable pulses given a phase shift operates in the following manner. The appearance at the point in time t, (Fig. 1 7) of logic 1 at the cathode of the diode 314, obtainable from the output of the oscillator 313 (Fig. 1 5), makes the diode 314 non-conductive and the capacitor 31 7 previously discharged begins to charge using the input current of the inverter 31 6. At the output of the latter there results logic 1, whereas the output of the AND-NOT gate 31 5 produces logic 0. At the point in time t2 (Fig. 1 7), the capacitor 31 7 (Fig. 1 5) charges to a voltage equal to the operating voltage of the flip-flop 31 6.The output of the AND-NOT gate 31 5 produces logic 1 which causes the diodes 319,321 to conduct. The capacitors 320, 323, previously discharged through the diodes 31 9, 321, begin to charge. Since the value of the capacitor 320 is twice the value of the capacitor 323 and the latter is selected to be equal to the value of the capacitor 317, the capacitor 323 tends to charge to the voltage equal to the operating voltage of the AND-NOT gate 322 and does so before the capacitor 320 charges to the voltage equal to the operating voltage of the inverter 31 8. The AND-NOT gate 322 operates at the point in time t3 (Fig. 17) while the inverter 318 (Fig. 15) operates at the point in time t4 (Fig. 17).

According to Fig. 17, the output of the AND-NOT gate 322 (Fig. 1 5) produces a pulse whose length is equal to the length of the pulse previously formed at the output of the AND-NOT gate 31 5 (Fig. 1 5) and time-shifted with respect to the former.

The operation of the inverter 327, AND-NOT gate 328, diodes 324, 325, capacitors 326, 329 of the generator 51 is analogous to that described for the inverter 31 8, AND-NOT gate 322, diodes 31 9, 321 and capacitors 320, 323 and is illustrated by the timing diagram of Fig. 17.

The summation unit 52 (Fig. 3) operates as follows. When a clear pulse from the output of the control unit 34, connected to the inputs 68 of the networks 48, 49, 50, is applied to the reset inputs of the bit positions of the add binary-decade counter 330 (Fig. 1 6) the latter is padded with zeros. A clear pulse is produced automatically, when the supply unit 75 (Fig. 3) is energized, or by depressing the button 269 (Fig. 8) of the control unit 34 so as to activate the apparatus.The r.f. pulses from the data outputs 69, 70, 71 (Fig. 3) of the networks 48, 49, 50, carrying data on the weight of the substance withdrawn from the given reservoir, are applied to the inputs of the OR gate 331 (Fig. 1 6). Thereafter, these pulses are applied to the counting input of the counter 330, are stored therein, and are applied in the form of a binary-decade code to the inputs of the decoding/indicating circuit 332 and to the inputs of the registering circuit 333. In the latter, the intermediate results relating to the metering of the amount of the substance and also these representing the total amount of the substance passed through the apparatus during the entire operational cycle are placed.

Described below are typical operations performed in the reservoirs 1, 2, 3 (Fig. 3). First consider the load and unload operations relating, by way of example, to the reservoir 1. When the reservoir loading means 8 (Fig. 4) is made open under the action of a liquid, the latter is led from the inlet collector 14 into the T-piece 84 and then passes into the reservoir 1 via the bellows 82. As the reservoir 1 is filled with the liquid the level of the latter rises until the float 92, together with the magnet 93 mounted thereon, reaches the preset upper range 25. The magnet 93 acts on the magnetcontrolled contact of the signalling means 22 at the lower limit of the preset upper range 25 and the means 22 therefore operates. As a result, the reservoir loading means 8 is closed and the flow of the liquid to the reservoir 1 is stopped.If the liquid level, during the above operations, reaches the upper limit of the preset upper range 25, the signalling means 22 operates again, as the magnet 93 acts on the other magnet-controlled contact of the means 22, arranged at that upper limit. The magnetcontrolled contacts of the signalling means 22, 26 of respective preset ranges 25, 29, upper and lower, are connected in parallel. When the liquid level and, therefore, the float 92 are located in the middle of the preset range, the magnet-controlled contacts of respective signalling means are open.

When the reservoir unload means 11 is open, the liquid is led out of the reservoir 1. The liquid level lessens and the liquid passes through the bellows 82 and the T-piece 84 into the outlet collector 1 5. When the float 92, together with the magnet 93, reaches the preset lower range 29, the signalling means 26 operates. Thus, the means 11 is closed and the flow of the liquid from the reservoir 1 is stopped. If the liquid level reaches the lower limit of the preset lower range 29, the signalling means 26 operates again.

The compensation of the hydrostatic components of the weight of the liquid during loading and unloading the reservoirs with the liquid delivered from under its surface is as follows. The reservoir 1 being weighed is loaded and the liquid is withdrawn via the bellows 82 at its bottom portion. The column of the liquid within the cross-section of the bellows 82 rest on the lower wall of the immovable T-piece 84 and is not taken into account in weighing the reservoir 1 with the liquid. As a result, the amount of the liquid in the reservoir 1 actually weighed is less that the amount of the withdrawn liquid, the difference being equal to the weight of the column of the liquid, whose cross-section amounts to the section of the bellows 82.The compensation of that column not included in the weighing result is carried out by virtue of the rod 90 rigidly fixed to the body 7 and having its cross-section equal to that of the bellows 82. The rod 90 is responsible for an additional force created in the reservoir 1 with the liquid and applied to the dynamometric pickup 4, with the result that the weight of the column of the liquid not included into the weighing result is compensated for at any level of the liquid within the limits of the preset upper and lower ranges 25, 29.

The method and apparatus of the invention make it possible to accurately determine the amount of a substance passed, for example, through product lines, in the form of a continuous flow. The above techniques of the method of the invention have a minimal influence on the inlet flow of the substance and provide for the formation of a continuous flow of the substance, which is necessary for normal operation of a given product line.The method utilizes a technique according to which the beginning of weight measurement, following the load or unload operation, is delayed with the result that more accurate weight determination of the amount of the substance is attained with the production rate of the basic process dealing with the transportation of the substance maintained at higher level, thereby ensuring greater economic effect as compared to the conventional methods of determinign the amount of the substance in which ordinary weighing means such as scales are used.

In the method of the invention it is to be noted that the loading is terminated within a preset upper range. The latter is determined in accordance with amount 0 of the substance fed into the reservoir and with the characteristics of the flow of said substance. The preset upper range is determined by the characteristics which are functionally related to amount 0 of the substance passed into the reservoir in the form of a continuous flow. Such characteristics involve the substance volume, the substance weight and the substance load time. The upper limit of the preset upper range, Q4, is determined by the value of the characteristic, corresponding to the capacity of the reservoir loaded. The lower limit of the preset upper range, 03, is determined by the value of the characteristic, corresponding to the end of loading the reservoir.The preset upper range, including the limits from Q3 to Q4, is characteristic of the end of reservoir loading, which makes it possible to take into account the possible variations of the characteristics of the substance flow and a transport delay related to the end of the load operation. In addition, the preset upper range allows for the use of the reservoir capacity to a maximal extent, in which case the overflow condition is eliminated when a continuous flow of the substance is introduced into the reservoir.

Likewise the preset lower range is also determined by the characteristics which are functionally related to amount 0 of the substance withdrawn from the reservoir in the form of a continuous flow.

Such characteristics are the volume and weight of the substance withdrawn and unload time. The upper limit of the preset lower range, 02, is determined by the value of the characteristic, corresponding to the end of the unload operation. The lower limit of the preset lower range, 0,, is determined by the value of the characteristic, corresponding to the emptied reservoir. The preset lower range within limits Q1 to Q2 is characteristic of the end of the reservoir unloading, which makes it possible to take into account the possible variations of the characteristics of the substance flow and a transport delay of the unload operation and provides for the equality of the amounts of the substance loaded and unloaded within time interval T.

Claims

1. A method of determining by weight the amount of a flowing substance, the method comprising directing the flowing substance into and out of a plurality of reservoirs in a cyclic sequence so that unloading each reservoir is maintained coincident with loading another of the reservoirs, and in which each reservoir is loaded to within a predetermined upper range, weighed after a time interval, then unloaded to within a predetermined lower range and reweighed after another time interval, and the amount of substance is computed from the difference in the weighings.

2. A method according to claim 1 in which the upper predetermined range depends on at least one of the substance volume, the substance weight and the loading time, and the lower predetermined range depends on at least one of the substance volume, the substance weight and the unloading time.

3. A method according to claim 1 or claim 2 in which the flowing substance is a liquid, and in which the liquid is damped when it is in the reservoirs.

4. A method according to claim 3 in which the liquid is introduced to and withdrawn from the reservoir at a level beneath its surface, and the weighing is compensated for any additional hydrostatic component.

5. Apparatus for determining by weight the amount of a flowing substance, the apparatus comprising a plurality of reservoirs suspended from dynamometric pickups which are rigidly fixed to a body, a control unit which is coupled to an inlet and an outlet of each reservoir and to an indicator which signals when the substance is present in any reservoir to within either predetermined upper or lower ranges, and a measuring unit, coupled to the control unit and each dynamometric pickup, which registers the weight of each reservoir with the substance present within the predetermined upper and lower ranges and relays data to a summation unit.

6. Apparatus according to claim 5 in which the measuring unit comprises a plurality of arithmetic processing networks each of which has a data input coupled via a respective frequency converter to a respective one of the dynamometric pickups, two trigger inputs and their reset inputs coupled to outputs of the control unit and two control outputs coupled to corresponding inputs of the control unit and an output connected to the input of the summation unit.

7. Apparatus according to claim 6 further comprising a time-mark generator with a plurality of outputs each coupled to a particular one of the arithmetic networks.

8. Apparatus according to claim 6 or claim 7 in which the arithmetic processing networks comprise subtract binary counters, groups of AND gates equal in number to the bit positions of the counters and coupled to corresponding outputs thereof, first add binary counters having their inputs set by respective outputs of the AND gates, overflow acknowledgment circuits having their inputs coupled to complement outputs of high-order positions of the first add binary counters, controllable switches with inputs used for the data inputs, the trigger inputs the reset inputs, and the time-mark inputs of respective arithmetic processing networks, and outputs used for the control outputs and the data outputs of respective arithmetic processing networks and have further inputs coupled to the outputs of the overflow acknowledgement circuits, and have their respective outputs coupled to counting inputs of the subtract binary counter, to other inputs of respective AND gates, to counting inputs of the first add binary counters, to reset inputs of the subtract binary counters and the first add binary counters, the network also comprising second add binary counters having their counting and reset inputs coupled to respective outputs of the controllable switches and having their complement outputs of low- and high-order positions coupled to corresponding inputs of the controllable switches.

9. Apparatus according to any one of claims 5 to 8 in which the substance is introduced into and withdrawn from the reservoirs by bellows connecting with and disposed beneath the reservoirs.

10. Apparatus according to claim 9 in which the reservoirs are hermetically sealed, and second pairs of bellows connecting with and disposed above the reservoirs pass any volatile component of the substance.

11. Apparatus according to claim 10 in which the bellows and second pair of bellows are aligned and have identical cross-sections.

1 2. Apparatus according to any of claims 5 to 11 in which the reservoirs are provided with dampers which rest on the surface of the substance.

13. Apparatus according to claim 12 in which the dampers comprise plates of smaller area than the cross-sectional area of its respective reservoir and which have an off-centre aperture through which an upright guide passes, the guide being fixed with relation to the reservoir.

14. Apparatus according to claim 12 or claim 1 3 in which a member is provided which compensates weight readings for any hydrostatic component of the liquid.

1 5. Apparatus according to claim 14 in which the member comprises a rod of greater length than the distance between the distal limits of the predetermined upper and lower ranges and which is disposed along the axis of symmetry of its reservoir and is aligned with and of the same cross-sectional area as the bellows.

1 6. A method of weight determination of the amount of a substance possessing fluidity quality, carried out in a continuous flow of the substance, comprising the steps as follows; periodically loading each of a number of reservoirs with the substance being fed continuously, which loading being terminated within a preset upper range determined by at least one of the characteristics including the volume and weight of the substance and load time; weighing each of said preset upper range after a time interval corresponding to the setup time for the reservoir with the substance; periodically unloading each of the reservoirs, which unloading being maintained in time coincidence with the loading of one of the remaining reservoirs and being terminated within a preset lower range determined by at least one of the characteristics including the volume and weight of the substance and unload time; weighing each of the reservoirs for the preset lower range after a time interval corresponding to the setup time for the reservoir with the substance; and determining the total amount of the substance using the results obtained during the weighing of the reservoirs with the substance for the preset upper and lower ranges.

1 7. An apparatus for weight determination of the amount of a substance possessing fluidity quality, carried out in a continuous flow of the substance, comprising a number of reservoirs, means for feeding the substance into the reservoirs and means for withdrawal of the substance from the reservoirs, coupled to reservoir loading and unloading means, said reservoirs being adapted to suspend from dynamometric pickups equal in number to the reservoirs and rigidly affixed to the body a control unit coupled to the reservoir loading the unloading means and to means for indicating the amount of the substance fed into the reservoirs and to means for indicating the amount of the substance withdrawn from the reservoirs, the means for indicating the amount of the substance fed into the reservoirs having signalling means for the preset upper range,

the means for indicating the amount of the substance withdrawn from the reservoirs having signalling means for the preset lower range, frequency converters, equal in number to the reservoirs, being coupled to the dynamometric pickups, a unit for measuring and registering the amount of the substance being coupled to the control unit and to the frequency converters, said metering/registering unit being provided with networks for arithmetic processing of the measured data and determining the weight of the reservoirs with the substance and also determining the weighing results relating to the loaded and unloaded reservoirs, said arithmetic

processing networks being equal in number to the reservoirs and having their data inputs coupled to respective frequency converter, having their respective two measurement trigger inputs and their respective reset inputs coupled to corresponding outputs of the control unit, and having their respective two control inputs coupled to corresponding inputs of the control unit, a summation unit having one input coupled to an output of the control unit, which is coupled to the reset inputs of the arithmetic processing networks, and having its other inputs, equal in number to the reservoirs, coupled to data inputs of the arithmetic process processing networks, and a time-mark generator having their outputs, equal in number to the reservoirs, coupled to respective time-mark inputs of the arithmetic processing networks.

1 8. Apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

1 9. A method substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.