DE102004041857A1 - Adjusting measuring device for determining filling level of container using propagation time technique, comprises storing echo curves for different positions of measuring device and selecting nominal curve - Google Patents

Abstract

The process involves mounting a measuring device on a container and emitting signals that are reflected from the surface of the contained substance. An echo curve (17) is determined from the reflected measurement signal, and indicates the signal amplitude in dependence on the propagation time or distance covered. The echo curves are stored for different installation positions of the measuring device. The individual curves are visualized as a curve group, and a nominal curve is selected based on actual, physical, measuring and process parameters.

Description

The The present invention relates to a method and a device for aligning a measuring device, that works according to the transit time measurement method and that for the determination the level in a container is used.

Measuring devices are often used in automation and process control technology to a Process variable such as Flow, level, pressure and temperature or a different physical and / or chemical process variable in a process flow to investigate. The applicant also includes measuring devices the name Micropilot or Prosonic produced and distributed, which work according to the transit time measurement method and serve a level a medium in a container to determine and / or monitor. In the transit time measurement method, for example, ultrasonic waves are transmitted over a Transducers or microwaves or radar waves emitted via an antenna and those on the media surface Reflected echo waves are calculated according to the distance-dependent transit time receive the signal again. From the term can be with the help of the known Propagation speed of the level of the medium in one container to calculate. The echo curve represents the received signal amplitude as a function of time or distance, with each reading the echo curve of the amplitude of one at a certain distance a surface reflected measurement signal corresponds.

The Runtime measurement method is basically divided into two preliminary investigations: which are, the time difference measurement, the duration of the duration of a transmitted high-frequency pulse signal for one covered Distance determined; Another widespread investigation is the determination of the frequency difference of the emitted high-frequency signal to the reflected, received high frequency signal (FMCW - Frequency Modulated Continuous Wave), where the frequency of the emitted High frequency signal is changed continuously.

in the Further will be no limitation made on a special preliminary investigation, but the parent Runtime measurement method used as measuring principle.

• – die Reflektionseigenschaften des Mediums,
• – baulich bedingte Störelemente im Abstrahlkegel des Sendeelementes,
• – Schüttkegelbildung,
• – Einfüllvorrichtungen und Rührwerke im Behälter und
• – die Ansatzbildung des Mediums an der Sende- und Empfangseinheit

einen starken Einfluss auf die Zuverlässigkeit und Verfügbarkeit der Messgeräte und der von ihnen ermittelten Messwerte. Die Auswirkungen dieser Einflussfaktoren auf das Messsignal können durch einen optimierten Einbau des Sendeelementes minimiert werden. Bei so genannten Laufzeitmessverfahren bzw. dem „Time of Flight"- Messverfahren, wie z.B. der freistrahlenden Mikrowellen- und der Ultraschall-Messtechnik, ist es für eine optimale Mess-Performance wichtig, die Messsituation mit Hilfe der Einbauposition der Antenne bzw. des Schallwandlers zu optimieren.Due to the measurement method according to the reflection principle, the quality of the measurement signal or the echo curve depends strongly on a wide variety of influencing factors for measuring instruments which operate according to the transit time measurement method. For example, have

• The reflection properties of the medium,
• - structurally related interference elements in the emission cone of the transmitting element,
• - Conversion of bulk material,
• - Filling devices and agitators in the container and
• - The formation of deposits of the medium at the transmitting and receiving unit

a strong influence on the reliability and availability of the measuring instruments and their measured values. The effects of these influencing factors on the measuring signal can be minimized by an optimized installation of the transmitting element. In the case of so-called time-of-flight measurement methods or the time-of-flight measuring method, such as free-radiating microwave and ultrasonic measuring technology, it is important for optimal measurement performance to increase the measuring situation with the aid of the installation position of the antenna or of the sound transducer optimize.

To The current state of the art requires the operator to optimize Aligning the antenna or the sound transducer, the position of the Transmitter and receiver gradually change and get one on the Display displayed characteristic (e.g. the intensity the amplitude of the level echoes in dB) with the associated memorize the antenna or sound transducer position for a rating the measurement situation in the tank container to be able to make. However, the known parameter does not allow a comprehensive statement about the Installation situation of an antenna or a sound transducer in one container or over the disturbances in the Vessel geometry, since only one parameter of the measurement signal, usually only the intensity of the amplitude the level echo, can be considered. Depending on the measurement situation is the interesting Range of measurement in the near or far range of the antenna or the sound transducer. There are interfering signals due to interference reflections the emitted microwave signal or ultrasonic signal in Neck or other disturbing Hindering elements. The useful echo of the filling level can be determined by the interfering signals covered in the echo curve be so that no evaluation of the level echo signal is possible. Will be as usual only the intensity of the level echo used as the evaluation criterion of the echo curve, so is the above aspect, namely the Störreflektionen in the near field area of the transmitting and receiving unit, when setting of the measuring device not considered. Thus, in this case, the orientation of the meter for one application is the Measurement in the near field range of the transmitting and receiving unit not suitable, or it is not tuned to the optimal measurement performance.

Furthermore, it is possible according to the current state of the art to display the echo function as a function of time on the display of the measuring device or a networked service tool and thus the current measurement situation at the current position to determine the transmitting and receiving unit. Such an apparatus for visualizing an echo curve or history data on a display unit is known from the patent application DE 100 52 836 A1 known. The disadvantage of this device is that it is not possible to visually compare the measuring signals under different installation situations of the measuring device. For these reasons, it makes sense to carry out an evaluation of the installation situation or the emission characteristic of the transmitting and receiving unit as a function of the measuring signal or the echo curve generated therefrom.

So that corresponding measurement signals can be recorded at different mounting positions, the position of the measuring device or the transmitting and receiving unit must be adjusted or the emission characteristic of the transmitting and receiving unit to be changed via a device. Such a device for changing the installation position by a mechanical alignment device is known from the patent application DE 101 06176 A1 known. Furthermore, a device for changing the emission characteristic of a planar antenna from the patent application DE 101 49 851 A1 known. A device for detecting a faulty installation situation of a flow meter in a test setup is from the patent application DE 102 30 607 A1 known. In this publication, a device is presented which detects the faulty installation situation of a vortex flow measuring device and forwards this error message to a control system. The disadvantage of these examples of an alignment device is that the operator needs great expertise or know-how to set or align the measuring device.

Of the Invention is based on the object, a simplified method and a device for determining the optimized alignment of the measuring device or show its transmitting and receiving unit.

The The object is achieved by a Method for aligning a measuring device for determining the filling level a product in a container solved according to the transit time measurement method, being the meter on the container being mounted, being over a transmitting and receiving unit irradiated a measuring signal into the container which is on a surface of the contents is reflected, wherein from the reflected measurement signal at least one Echo curve showing the signal amplitude values of the measurement signal as a function of from the term or the completed Running distance is determined, wherein at least a first Installation position of the measuring device or a first electronically generated emission characteristic of Transmitter and receiver unit is set, wherein the first echo curve is stored and visualized, wherein at least a second Installation position of the measuring device or a second electronically generated radiation characteristic of Transmitting and receiving unit is set, wherein at least the second echo curve is stored and also visualized, wherein the individually stored echo curves together as a family of curves be visualized, and using current, physical, metrological and / or process-related parameters from the set of curves at least one desired echo curve is selected.

the Operating personnel of the measuring device is it possible by this method a visual assessment of multiple echo curves or measurement signals simultaneously make at least two different echo curves or Measurement signals are visually compared with each other and distinctive points of the Echo curve or the measured signals evaluated. By this procedure let yourself a better rating with different rating parameters since it is no longer just a determined comparison value, e.g. the amplitude value of the level echo, to disposal stands. By saving the selected echo curve they can at any time for further processing or presentation from the memory be charged high. The storage can be done by a selection action of the operator by, for example, via the Input unit, the storage of the echo curve in the memory unit is initialized. Furthermore, as an alternative embodiment is an automatic Storage of the measured echo curve feasible by the previously stored echo curve or the occupied by this memory area either overwritten or the new echo curve into another free memory area is stored.

The used for archiving the echo curves memory unit is in Commissioning device and / or in the meter self-integrated. But there are also external storage media, the to the device via a Be connected to the interface or via a field bus in other, distant devices can be used for archiving the echo curves used.

to Clarification of the association between an echo curve and the alignment of the measuring device can additionally another comment about Added an input unit and assigned to the display unit, the associated echo curve, be visualized.

To determine the measurement signal according to the transit time measurement method, for example, as already described above, a high-frequency measurement signal is transmitted and the reflected measurement signal is measured after a certain time. From a variety of such high-frequency measurement signals is through a sampling method or a sequential sampling which scans the recorded measurement signals at specific intervals, generates a lower-frequency echo curve or a digitized envelope. This additional processing step of the measuring signal is carried out because there are no correspondingly cost-effective data processing units, for example DSPs (digital signal processors), which can reliably process high-frequency measuring signals. Depending on the hardware or data processing unit used, however, an evaluation of the high-frequency measurement signals in real time is possible. Of course, the method can also be realized by the use or processing and visualization of high-frequency measurement signals instead of the lower-frequency envelopes or echo curves.

A advantageous embodiment of the solution according to the invention suggests that to select the Target echo curve an amplitude value of the level echo, the signal width the level echo, at least a false echo the echo curve, the signal to noise ratio of the echo curve, and / or the ringing in the near field area of the transmitting and receiving unit as current, physical, metrological and / or process-related Parameter is used. There are a lot of different ones Evaluation parameters that the operating personnel to evaluate the measurement situation can draw on. The above parameters are an excerpt from a variety of parameters, with the knowledge of the best possible alignment the transmitting and receiving unit can be set. Furthermore is it also possible the correct functioning of the measuring device on the basis of the pictured Determine and evaluate echo curves. Through the optimization the installation position should be the availability, i.e. the average time share during which the meter is in the intended functional state is increased become. Since not only one parameter is considered, but an optimum between different influencing factors with the help of the determined Evaluation parameter of the echo curves is found here best Installation position for the different applications are found.

A very advantageous variant of the solution according to the invention can be seen in that the most recently shown or selected via an input unit echo curve distinguishable from the rest Echo curves is marked. To highlight the currently recorded Echo curve from the rest Echo curves in the set of curves will do this in a different way and Way than the rest shown. There are various types of echo curves that can be distinguished Possibilities: The the echo curve to be demarcated may e.g. flashing, lighter or thicker than the other echo curves appear on the display unit. There are also other forms of representation of the demarkeren echo curve executable. About the Input unit, it is possible select a specific echo curve and to mark.

A very advantageous variant of the solution according to the invention can be seen in that each a partial curve of the echo curve visualized or stored becomes. Instead of the entire echo curve can also be a sub-area or a partial curve are used for the evaluation, e.g. is the near field area of the transmitting and receiving unit of about 0-3 m of interest, because there the ringing of the transmitting and receiving unit can be observed. The advantage of this embodiment is that itself the evaluation is limited to only a subrange of the echo curve and thereby a faster repetition rate of the representation due to smaller amount of data possible is. Furthermore, a visual assessment turns into one Partial curve by the operator easier because the resolution of the Representation is enlarged, and the differences of the different echo curves more visible become.

A Particularly advantageous development of the solution according to the invention proposes that the echo curve is measured by at least one curve point or at least one curve area of at least the echo curve is selected and that at least the coordinates of the corresponding measured value be determined. Through the vertical and horizontal selection lines or the selection lines of the ordinate and the abscissa may be one digit or an area of the selected one Echo curve can be selected or marked with the input unit. The values of the ordinate and the abscissa or the coordinate values of the curve point are determined. On the other hand, the operator selects a curve area on the display unit, the associated difference value the two abscissa values and the two ordinate values of the curve points determined. Furthermore, by means of the selection function a subrange of the Echo curves selected which, by means of a magnification function, which can be turned on by the input unit, the selected area enlarged on represents the display unit. The value of the ordinate indicates e.g. the intensity of the measurement signal mostly in dB again, and the value of the abscissa represents the term or the completed Way of the measuring signal. With this function can thus any Echo curve will be measured, so that the operating personnel not only visually assessed the different echo curves, but also readings from the echo curves to be evaluated for the evaluation of the illustrated Echo curve can attract.

An advantageous embodiment of the solution according to the invention suggests that the measuring device and / or the transmitting and receiving unit be moved in the alignment process from the first mounting position to the second mounting position in predetermined spherical angular steps / and that a position value of the current mounting position is determined. The installation position of the transmitting and receiving unit or their Hauptabstrahlachse in space has been determined by the polar coordinates φ and,, as this is an easy way to determine the angular position data or the orientation of the transmitting and receiving unit or the entire meter and store ,

According to one advantageous embodiment of the solution according to the invention suggested that the current position value of the current echo curve is stored concurrently and that the current position value visualized associated with the current echo curve. By the Assignment of the position data to the associated echo curve is the Operating personnel easier, the position of the selected optimal echo curve to drive or to find again. This is it is possible a simple direct relationship of the angular position data of the transmitting and receiving unit to create the measured echo curve. For this the transmitting and receiving unit must be at a starting angular position be calibrated, from which the measurement of the position data takes place.

The Task is about it According to the invention by a device for aligning a measuring device for determining the level a product in a container solved according to the transit time measurement method, wherein the device comprises a transmitting and receiving unit, at least a storage unit in which the installation position data of the measuring device and the echo curves are stored, at least one data processing unit, comprises at least one display unit and at least one input unit, and wherein an alignment device is provided, the orientation of the measuring device and / or the transmitting and receiving unit defined changes. In the device is a transmitting and receiving unit provided, the measuring signals in the direction the surface of the contents and that receives the reflected measurement signal. The received measurement signal is processed by the data processing unit, by e.g. the noise is filtered out and an echo curve or an envelope by a scanning method of the emitted and reflected Measuring signal is generated. The echo curves are displayed on the display unit visualized and / or stored in the storage unit and archived. About the Input unit are different functions of the meter selectable.

A expedient embodiment the device according to the invention is that the alignment device as an electronic Aligning device is designed which the emission characteristics and / or the main radiation axis of the transmitting and receiving unit of the measuring device changed by a variable control of the transmitting and receiving unit. at this embodiment is the meter via a Stuck tightly on the container assembled. It is omitted the mechanical alignment device, which seals the process space difficult. The main emission axis of the radiation lobe of the transmitting and receiving unit or their radiation characteristics can be through Set a clever control of the transmitting and receiving unit.

The Activation can be done in two ways, in which different ones Wave modes of the high-frequency measurement signal, which is a different Have emission characteristic of the electromagnetic radiation, are excited and emitted in the transmitting and receiving unit, or by being at the transmitting and receiving unit to a group antenna or planar antenna. Planar and array antennas, e.g. patch, Slot, microstrip array antennas are of a variety of individual Constructed transmitting elements, which with different phase and / or intensity be controlled, resulting in the far field of the transmitting and receiving unit generate an adjustable, directed electromagnetic field leaves.

A expedient alternative Embodiment of the device according to the invention is that the alignment device as a mechanical Aligning device is designed, the spatial position of the transmitting and receiving unit and / or the meter changed. The orientation of the meter takes place, for example, mechanically, pressure and gas-tight over a Rotary wedge flange or a ball joint. By using a mechanical alignment device or adjustment unit is the operator quite simply possible, the angular position of the transmitting and receiving unit gradually change.

A very advantageous variant of the solution according to the invention can be seen in the fact that a drive is provided which automatically changes the installation position of the measuring device and / or the transmitting and receiving unit by means of the mechanical alignment device. The mechanical alignment device can also be automated by a drive. As drive to the spherical alignment of the measuring device, for example, an electric stepper motor or a piezo drive can be used. This embodiment of the invention is fundamentally important in an automated alignment or adjustment of the transmitting and receiving unit and evaluation of the echo curves, as can be approached automatically by the drive, the desired position. The control of the drive, such as the stepper motor or the piezo drive, the mechanical Alignment device is operated by the electronics of the meter itself or by another external control unit or the commissioning device.

A advantageous embodiment the solution according to the invention consists in that a position sensor is provided, which is the current one Position value of the transmitting and receiving unit and / or the measuring device determined. The position sensor determines the angular position data of the measuring device or the transmitting and receiving unit by this either the location of the meter measures or determines the adjustment path of the position change. As built-in position sensor For example, at least one inclination sensor and / or at least an incremental encoder can be used. About the tilt sensors can the current angular position is determined, and the current position value can over a data processing unit on the display unit, the associated echo curve assigned, displayed or stored in memory. With help of at least one incremental encoder, the angle or path, by which the transmitting and receiving unit was adjusted determined and these relative values can in turn be Processed data processing unit and on a display unit, the associated Echo curve assigned, displayed or stored in memory.

A Particularly advantageous development of the solution according to the invention proposes that a commissioning device is provided, the at least one position sensor, at least a storage unit, at least one data processing unit, at least one display unit, at least one input unit and at least one data interface, through which the Inbetrebnahmegerät on the Data line with the meter communicates. In this additional device is a integrated, self-sufficient adjustment unit. This adjustment unit communicates with the meter and the automatic, mechanical alignment device with drive or the automatic electronic alignment device via a Data interface e.g. a hard-bus, a service interface, etc. The commissioning device invites you either the data of the echo curve from the measuring device in the commissioning device and provides the echo curve and the position values on the display unit of the commissioning device or the commissioning device transmits the position data into the meter and put these together with the echo curve on the display unit of the meter Depending on the design are in the memory of the meter or of the commissioning device these data are stored, and there they are synonymous for both equipment available for wide processing.

The Use of such a commissioning device is particularly than meaningful if the meter or the transmitting and receiving unit is firmly installed and the main direction of emission or the radiation characteristic the transmitting and receiving unit via a variable control takes place. In this embodiment deleted the implementation of one or more position sensors in the gauge or in the commissioning device. however must be for each radiation characteristic or for each main radiation direction the transmitting and receiving unit, the actual control of the individual elements the group antenna in the memory unit of the meter or of the commissioning device be stored so that the generated radiation characteristics or Main emission direction of the transmitting and receiving unit of the corresponding Echo curve can be assigned.

According to one further advantageous embodiment of the solution according to the invention provided that the commissioning device via a fastener while the process of aligning the meter attached to the meter is. So that, for example, integrated in the commissioning device Position sensors the exact position of the measuring device or the transmitting and receiving unit can detect, the commissioning device must be flush with gauge be attached. The commissioning device is connected via a fastening element, e.g. a snap closure, a clamp, a connector, a magnet, etc., fixed to the meter.

A Another advantageous embodiment of the invention is that at least implemented an evaluation algorithm in the commissioning device or in the measuring device That is, an automated evaluation of each echo curve or the family of curves based on at least one current, physical, metrological and / or process-related parameters, and that the initialization the orientation of the meter and the evaluation is automatic and / or event-driven. The term "event-driven" is understood to mean that a new alignment process, for example, after expiration of a defined Time span, when reaching a defined level or when falling below a defined amplitude of the level echo of the echo curve triggered becomes. This further embodiment is particularly advantageous applicable in containers with strongly changing Surfaces, where in dependence a re-adjustment is performed by defined events. Through this automated adaptation to the changed specifications of the Process, this process is particularly suitable for solid applications, where the measurement situation in the container with time or due of deposits of the solid or of the agglomeration changes.

Of the Evaluation algorithm consists of mathematical functions, which determine the characteristics of the echo curves, and image signal processing the echo curves representing the echo curves with a stored target echo curve compares ,. The evaluation by the evaluation algorithm will turn by a visual assessment of the operator suitable for found echo curves evaluated by the evaluation algorithm were reviewed, and if necessary corrected.

The The invention will be explained in more detail with reference to the following drawings. to Simplification in the drawings are identical parts with the same Reference numerals have been provided. It shows:

1 An embodiment of the measuring device according to the invention with some of the possible interference and the associated echo curve with the corresponding false echoes,

2 An embodiment of the measuring device according to the invention with a plurality of possible transmitting and receiving units and a mechanical adjustment unit,

3 3 shows a schematic overall view of a measuring device mounted on a container with a mechanical alignment device for the transmitting and receiving unit and with an attached start-up device,

4 a schematic overall view of a permanently mounted on a container measuring device with a transmitting and receiving unit having different radiation characteristics,

5 an enlarged section of the display unit of in 2 represented measuring device, and

6 a schematic representation of an embodiment of the commissioning device.

In 1 is on a container 2 in a neck 4 a measuring device 1 mounted, which after the transit time measurement the level 28 a medium 6 in the container 2 determined. As disturbing installations 23 For example, an agitator, a cooling tube coil and a level measuring device installed in the container wall are shown in the illustration, but there are also other interference elements not explicitly illustrated in the drawing 23 that can influence the measurement. One of the measuring situation in the container 2 corresponding echo curve 17 is proportional to the height of the container 2 shown. The pictured echo curve 17 represents the amplitude 18.a the sampled, emitted and reflected measuring signal as a function of the running distance x or the transit time t. The disturbing influences of installations 23 in the container 2 and the surface 6.a of the medium 6 are via reference lines directly to the corresponding level echo 18 and the corresponding false echoes 19 in the echo curve 17 assigned, so that you can capture the cause-effect principle at a glance. In the beginning of the echo curve 17 is the ringing 20 to see that due to multiple reflections in the transmitting and receiving unit 10 or the neck 4 arises, and / or also by accumulation at the transmitting and receiving unit 10 can arise.

In 2 is the measuring device 1 in an enlarged view with a plurality of different transmitting and receiving units 10 , all of which work according to the transit time measurement method. About the transducer 10.b Ultrasonic waves are generated and radiated into the free space. For the emission of microwave pulses - as shown in the illustration - different types of antennas such as a planar antenna 10.a , a horn antenna 10.c , a rod antenna 10.d and a parabolic mirror antenna 10.e used. About the display unit 11 and the input unit 12 can be that measuring device 1 serve.

The measuring device 1 is in most applications via a flange 7 in a neck 4 on the container 2 attached. But there is also the possibility of the meter 1 via a screwed connection on the container 2 to attach what is not in the representations 2 . 3 and 4 is shown explicitly. In the 2 is only the possibility of mechanical alignment of the transmitting and receiving unit 10 via a mechanical alignment device 3.a shown as a pressure and gas-tight ball joint, but are also other alignment devices 3 , such as rotary wedge flanges, etc. as an alignment device 3 used.

An example of application of a mechanical alignment device 3.a a measuring device 1 is in 3 to see. In the illustration is a measuring device 1 shown, which basically consists of a transmitting and receiving unit 10 that are in the container 2 located and an electronics and power unit located in a housing outside the closed container 2 , and not explicitly shown in the diagram, composed. This transmitting and receiving unit 10 and here especially a sound transducer 10.b is over a neck 4 in the container 2 introduced and by a two-sided flange 7 on the container 2 attached. A mechanical alignment device 3.a is in the area where the meter is 1 on the container 2 is attached, formed, which via a drive 33 can be adjusted automatically. The measuring device 1 has a supply line 36 and a fieldbus 35 , On the meter 1 is a commissioning device 8th attached. Both communicate via a data medium tung 9 together. The recorded echo curves 17 be on the display unit 11 of the meter for visual display, and via the input unit 12 becomes the operation of the meter 1 performed.

The measuring device 1 or the transmitting and receiving unit 10 comes with the mechanical alignment device 3.a via a drive 33 from the first installation position 29.a in the second mounting position 29.b adjusted. Due to the orientation of the transmitting and receiving unit 10 becomes the radiation lobe or the Abstrahlkegel of the interfering elements 23 , For example, an inlet pipe, directed away, so that as possible no more measuring signal on the surfaces of interfering elements 23 incident. Rather, an attempt is made by the optimized alignment of the transmitting and receiving unit 10 as much signal intensity in the direction of the surface 6.a of the contents 6 to send and reflected again in the receiver of the transmitting and receiving unit 10 to obtain.

The power supply of the measuring device 1 itself takes place via a supply line 36 , and communication with a remote control center or with other measuring devices 1 is via a fieldbus 35 , which supports all known communication standards, such as PROFIBUS-PA or FOUNDATION FIELDBUS. In particular, it is provided, the meter 1 over the fieldbus 35 to provide the necessary energy. For this is the meter 1 preferably designed according to standards and regulations as a 4-20 mA two-wire meter. Due to the communication connection of the commissioning device 8th or of the measuring device 1 over a fieldbus 35 to a remote control center is also an automated alignment of the meter ( 1 ), which is started and evaluated by the control center.

To the functioning of the measuring device 1 is the following to say: From the meter 1 or from the transmitting and receiving unit 10 is a broadband microwave or ultrasonic pulse signal in the measuring chamber or in the container 2 sent out. At the in the radiation cone of the transmitting and receiving unit 10 located surfaces of objects, such as interfering elements 23 or contents 6 , the waves are reflected by the law of reflection at the same angle to the solder of the surface again. As a result, on each surface, in the radiation cone of the transmitting and receiving unit 10 is, depending on the angle of incidence and the material of the reflector, a reflection signal in the transmitting and receiving unit 10 reflected back. From the term of the surface 6.a of the contents 6 reflected back measurement signal is the level 28 of the contents 6 calculated. There are a multitude of different disturbing elements 23 that affect the quality of the measurement of the echo curve 17 Influence, eg installations 23 in the container 2 , Agitators, nozzles 4 , Approach to the transmitting and receiving unit 10 , Foam and Schüttkegelbildung 5 , etc.

The orientation of the transmitting and receiving unit 10 Incidentally, this is also necessary with the FMCW method and is also carried out there.

In 4 is a schematic representation of the meter 1 that has a flange 7 on a container 2 is mounted, with an electronic alignment device 3.b to see. The structure of the measuring device 1 is essentially identical to the one in 3 shown, however, is the installation position 29 of the measuring device 1 firmly; on a mechanical alignment device 3.a became in favor of an electronic alignment device 3.b waived.

The change in the orientation of the radiation characteristic 34 the transmitting and receiving unit 10 is by a variable control or by a different excitation of the transmitting and receiving unit 10 reached. For this embodiment, a transmitting and receiving unit 10 , For example, a planar antenna 10.a , used with single controllable elements. These elements of the transmitting and receiving unit 10 or the planar antenna 10.a are driven with different phase position and intensity of the measurement signal, resulting in the far field of the planar antenna 10.a the different Teilabstrahlcharakteristiken of the individual elements overlap and have a predetermined emission characteristics 34 or main emission axis 22 the transmitting and receiving unit 10 established. About this electronic alignment device 3.b Thus, the emission cone or the main emission axis can 22 the transmitting and receiving unit 10 in the space of the container 2 be pivoted in the way that first a first electronically adjustable radiation characteristic 34.A and then a second electronically adjustable radiation characteristic 34.b is produced.

5 shows a section of the display unit 11 and input unit 12 from a known measuring device 1 - in accordance with art 2 . 3 and 4 shown - as it is used for the determination and monitoring of process variables in process automation. On the display unit 11 become the echo curves recorded in different areas 17 , the associated current position value 25 and the readings 21 displayed. The input unit 12 is shown symbolically in the illustration as a menu-guided entry by three feeler elements, but there are other controls, such as a touch pad, a touch screen, a joystick, etc. as input unit according to the invention 12 used. To visualize the metrological conditions in the container 2 are the abgespei saved or current echo curves 17 . 17.a - 17.d as a family of curves in a coordinate system on the display unit 11 shown.

The echo curve (s) 17 , which the operator wants to use for evaluation, can / can via an input unit 12 selected and in the storage unit 13 be deposited. The stored echo curves 17 will be in the alignment mode of the meter 1 together with the selected or the current echo curve 17.a on the display unit 11 shown. The last generated echo curve 17.a or a manually selected echo curve 17.a is in a prominent display mode on the display unit 11 shown so that they differ from the remaining echo curves 17.b . 17.c . 17.d visually stands out.

About the input unit 12 can be accessed via a guided menu or via the screen pointer 33 certain curve points or curve areas of the echo curve 17 with a selection line the respective ordinate value 31 and abscissa value 30 highlight and select. The measured values determined in this way 21 be on the display unit 11 shown. About the input unit 12 can have a specific echo curve 17.a be selected from the bevy of echo curves. If this is not done, always the last recorded or selected echo curve 17.a selected and through a striking presentation of the other echo curves 17 optically lifted. The position data 25 the selected or the last generated echo curves 17.a are also in the display unit 11 displayed.

In 5 is in a Cartesian coordinate system, where the amplitude 18.a represents the sampled, emitted and reflected measurement signal as a function of the running distance x or the transit time t, a set of curves of different echo curves 17 in different installation positions 29 of the measuring device 1 or with different emission characteristics 34 the transmitting and receiving unit 10 shown. The echo curves 17 are comparable under the following criteria: The current or selected echo curve 17.a points towards the third echo curves 17.c and the fourth echo curve 17.d a more pronounced level echo 18 with a higher amplitude 18.a on, however, is the decay characteristic or the ringing 20 the third echo curves 17.c and the fourth echo curve 17.d in the near field area of the transmitting and receiving unit 10 lower. The second echo curve 17.b shows in the near field area still a stronger decay characteristic or ringing 20 as all other echo curves 17 , which negatively affects a measurement in the near field area of the transmitting and receiving unit 10 affects, but the amplitude is 18.a of the level echo 18 in the far field area of the transmitting and receiving unit 10 the largest, whereby in this area very good measurement results of the level 28 are to be expected. At the third echo curve 17.c in the 5 you can see that the amplitude 18.a the false echo 19 is much larger than the associated level echo 18 , This constellation is for a measurement of the level 28 mostly unsuitable: If the level 28 of the contents 6 in the near field area 24 the transmission and reception area 10 or in the area of the false echo 19 reaches, the level echo is 18 from the stronger false echo 19 covered, so no exact determination of the level 28 is possible. Also the signal width 18.b the level echoes 18 is used to evaluate the echo curves 17 used.

An unwanted consequence of false echoes 19 or reflections on interfering elements 23 or from the formation of different modes in the transmitting and receiving unit 10 is the so-called ringing 24 , The ringing 24 shows up in that the echo curve 17.b does not drop abruptly, but slowly loses amplitude. This bell edge can be the echo signal 18 in the assigned measuring range, or it can coincide with the echo signal 18 so superimpose, so that no usable measurement signal in the vicinity of the transmitting and receiving unit 10 is available.

Via a selection function in the user guidance of the measuring device 1 or the first time the instrument is put into operation, the meter switches off 1 in the operating mode by adjusting the orientation of the transmitting and receiving unit 10 is possible.

6 shows a schematic representation of the commissioning device 8th pointing to the meter 1 via a fastening element or a holding mechanism, such as a magnet or a latching support, is placed flush. At the commissioning device 8th it is a stand-alone device with a display unit 11 , via which the measured data, the echo curves 17 . 17.a and the operator visualization of the commissioning device 8th be displayed and with an input unit 12 , which are used to operate the commissioning device 8th and the via the data interface 15 connected measuring device 1 is used. The measured echo curves 17 . 17.a and the position data 25 the position sensors 16 be in the data processing unit 13 processed and in the storage unit 14 filed, if this echo curve 17.a was selected by the operator for storage and display. Via the data interface 15 and over the data line 9 communicates the commissioning device 8th with the meter 1 , The communication between the meter 1 and the commissioning device 8th can also with the power supply of the commissioning device 8th over the same data line 9 done in a two-wire or four-wire technology. The illustration shown has the In commissioning device 8th a separate supply line 36 that the commissioning device 8th energized, and a fieldbus 35 however, which enables communication with a remote control center or with other devices, but is also the power supply and the communication over the same data line 9 (Two-wire technology) conceivable. Also possible is wireless communication via radio. This is not specifically in the 6 shown, however, this embodiment is also feasible in the device according to the invention. The display unit 11 , the input unit 12 , the data processing unit 15 , the position sensor 16 and / or the storage unit 14 can both in the commissioning device 8th or in the meter 1 be integrated as well as in both at the same time.

Another variant of the application of an adjustable transmitting and receiving unit 10 is it, from the echo curves 17 depending on the adjustment angle of the transmitting and receiving unit 10 were taken, a three-dimensional image of the interior of the container 2 to generate. A three-dimensional image of the interior is in the evaluation of interference signals 19 in the measurement signal of great benefit, as from the three-dimensional map of the interior of the container 2 many statements about the disruptive effects can be obtained. For this application is a fully automated process of measurement with the control of the alignment unit 3 through the meter 1 and / or a commissioning device 8th very relieving. Thus the three-dimensional map of the container 2 can be recorded, the radiated measurement signal must have convergent radiation properties, for example, the radiation beam of a microwave must be able to be focused on a dielectric lens system. A scan of the interior of the container 2 with a non-focused or divergent radiation cone results in the recording of the interior of the container 2 a non-meaningful measurement signal.

1

gauge

2

container

3

alignment

3.a

mechanical alignment

3.b

electronic alignment

4

Support

5

Einfüllkegel or bulk cone

6

Contents or medium

6.a

surface

7

flange

8th

start-up Switch

9

data line

10

Send- and receiving unit

10.a

planar antenna

10.b

ultrasonic sensor

10.c

horn antenna

10.d

rod antenna

10.e

parabolic antenna

11

display unit

12

input unit

13

Data processing unit

14

storage unit

15

Data Interface

16

position sensor

17

Echo curve (s)

17.a

selected or current echo curve

17.b

second echo curve

17.c

third echo curve

17.d

fourth echo curve

18

echo signal the level or level echo

18.a

Amplitude value, amplitude

18.b

signal width

19

False echo, interference signals

19.a

SNR

20

Ring

21

readings

22

Main radiation axis

23

fittings, disturbing elements

24

near field

25

current position value

26

running time

27

running track

28

level

29

installation position

29.a

first installation position

29.b

second installation position

30

abscissa or abscissa value

31

ordinate or ordinate value

32

drive

33

screen pointer

34

radiation or directional characteristic

34.A

first electronically adjusted emission characteristic

34.b

second electronically adjusted emission characteristic

35

fieldbus

36

supply line

Claims (16)

Method for aligning a measuring device ( 1 ) for determining the filling level ( 28 ) of a product ( 6 ) in a container ( 2 ) according to the transit time measurement method, whereby the measuring device ( 1 ) on the container ( 2 ) is mounted, wherein via a transmitting and receiving unit ( 10 ) a measuring signal in the container ( 2 ) is irradiated, which on a surface ( 6.a ) of the product ( 6 ) is reflected, wherein from the reflected measurement signal at least one echo curve ( 17 ), the signal amplitude values of the measuring signal as a function of the transit time ( 26 ) or the distance traveled ( 27 ), is determined, wherein at least a first installation position ( 29.a ) of the measuring device ( 1 ) or a first electronically generated emission characteristic ( 34.A ) of the transmitting and receiving unit ( 10 ), the first echo curve ( 17 ) is stored and visualized, wherein at least a second mounting position ( 29.b ) of the measuring device ( 1 ) or a second electronically generated radiation characteristic ( 34.b ) of the transmitting and receiving unit ( 10 ), wherein at least the second echo curve ( 17 ) is stored and also visualized, wherein the individually stored echo curves ( 17 ) are visualized together as a family of curves, and wherein at least one desired echo curve is selected on the basis of current, physical, metrological and process-related parameters from the set of curves. Method according to Claim 1, in which an amplitude value (15) is selected for selection of the desired echo curve ( 18.a ) of the level echo ( 18 ), a signal width ( 18.b ) of the level echo ( 18 ), at least one false echo ( 19 ) of the echo curve ( 17 ), a signal-to-noise ratio ( 19.a ) of the echo curve ( 17 ), and / or the ringing ( 20 ) in a near field area ( 24 ) of the transmitting and receiving unit ( 10 ) is used as a current, physical, metrological and process-related parameter. Method according to claim 1, wherein the respectively last shown or via an input unit ( 12 ) selected echo curve ( 17.a ) distinguishable from the remaining echo curves ( 17 ). Method according to claim 1 or 3, wherein in each case a sub-curve of the echo curve ( 17 ) is visualized or stored. Method according to claim 1, 3 or 4, wherein the echo curve ( 17 ) is measured by at least one curve point or at least one curve region of at least the echo curve ( 17 ) and at least the coordinates of the corresponding measured value ( 21 ) be determined. Method according to claim 5, wherein the measured value ( 21 ) is stored and / or visualized by the curve point or a curve area. Method according to claim 1, wherein the measuring device ( 1 ) and / or the transmitting and receiving unit ( 10 ) during the alignment process from the first installation position ( 29.a ) to the second installation position ( 29.b ) is moved in predetermined spherical angular steps and wherein a position value ( 25 ) of the current installation position ( 29 ) is determined. Method according to claim 7, wherein the current position value ( 25 ) of the current echo curve ( 17.a ) and in which the current position value ( 25 ) of the current echo curve ( 17.a ) is visualized. Device for carrying out the method according to one or more of claims 1 to 8, wherein the device has a transmitting and receiving unit ( 10 ), at least one storage unit ( 14 ), in which the installation position data of the measuring device ( 1 ) and the echo curves ( 17 ), at least one data processing unit ( 13 ), at least one display unit ( 11 ) and at least one input unit ( 12 ), and wherein an alignment device ( 3 ), which determines the orientation of the measuring device ( 1 ) and / or the transmitting and receiving unit ( 10 ) defined changes. Apparatus according to claim 9, wherein the alignment device ( 3 ) as an electronic alignment device ( 3.b ) is designed, the the radiation characteristic ( 34 . 34.A . 34.b ) and / or the main emission axis ( 22 ) of the transmitting and receiving unit ( 10 ) of the measuring device ( 1 ) by a variable control of the transmitting and receiving unit ( 10 ) changed. Apparatus according to claim 9, wherein the alignment device ( 3 ) as a mechanical alignment device ( 3.a ), which determines the spatial position of the transmitting and receiving unit ( 10 ) and / or the measuring device ( 1 ) changed. Apparatus according to claim 11, wherein a drive ( 33 ) provided by means of the mechanical alignment device ( 3.b ) the installation position ( 29 ) of the measuring device ( 1 ) and / or the transmitting and receiving unit ( 10 ) automatically controls. Apparatus according to claim 11, wherein a position sensor ( 16 ), which determines the current position value ( 25 ) of the transmitting and receiving unit ( 10 ) and / or the measuring device ( 1 ). Apparatus according to claim 9, 10 or 11, wherein a commissioning device ( 8th ) is provided, the at least one position sensor ( 16 ), at least one storage unit ( 14 ), at least one data processing unit ( 13 ), at least one display unit ( 11 ), at least one input unit ( 12 ), and at least one data interface ( 15 ), through which the commissioning device ( 8th ) via the data line ( 9 ) with the measuring device ( 1 ) communicates. Apparatus according to claim 9, 10 or 11, wherein the commissioning device ( 8th ) via a fastener during the process of alignment of the measuring device ( 1 ) on the measuring device ( 1 ) is attached. Apparatus according to claim 9, 10, 11 or 14, wherein at least one evaluation algorithm in the commissioning device ( 8th ) or in the measuring device ( 1 ), which provides an automated evaluation of the individual echo curves ( 17 ) or the set of curves on the basis of at least one current, physical, metrological and process-related parameter and wherein the initialization of the orientation of the measuring device ( 1 ) and the evaluation is automatic and / or event-driven.