SU750406A1 - Dc device for testing magnetic induction measures - Google Patents

Description

laziness of current in coils. A synchronous detector connected to the second switch instrument via an integrator, the signal input of which is connected to the output of the electronic unit of the magnetometer, and the control input connected to the alternating voltage generator through the threshold device T2 o

The known device operates as follows.

The second switch instrument controls the absence of external magnetic fields in the coils, which are compensated by the compensator. By varying the inductance of the stores and the resistances of the resistors, the phases and amplitudes of the alternating currents in the coils are equal, which is controlled by both switches. In this case, at a given frequency f, the ratio of the constant K of the coil being tested to the known constant K of the model coil is determined by the resistance value R / | and R j resistors and the mutual inductance value M of the store from the expression:

K RjlTtfM

R

v,

These operations are performed at least eight times with different directions of current in the coils, and the constant K y is defined as the average result of eight measurements.

A disadvantage of the known device is the low accuracy of calibration due to the unaccounted resistance of the coils themselves and the lead wires.

The aim of the invention is to improve the accuracy of verification.

This goal is achieved by the fact that a device for calibrating alternating current magnetic induction measures containing an exemplary coil installed inside a testable one, two resistors, an inductance store, an alternating voltage generator, a ferrosonde probe installed in the center of the coils and an output connected to the electronic unit ittometer, and the input to the external noise compensator, a synchronous detector, the signal input of which is connected to the output of the magnetometer, and its output is connected via an integrator to the null indicator, the threshold element t, the input of which is connected to the alternating voltage generator, and the output to the control input of the synchronous detector / constant voltage meter, switches, is supplied with a constant voltage source, the first output of which is connected through terminals of the first switch directly coaxially, the second output is through an inductance store and two resistors of the second pair of contacts of the aforementioned switch are short-circuited and connected through an exemplary coil to one of the outputs of the alternating voltage generator, the second output of which is connected to the common point of two resistor stores, to which one of the inputs of the constant voltage meter is also connected, the other input of which is connected to the poles of the constant voltage source through a single-pole three-position switch wives

FIG. 1 shows a block diagram of the device; in fig. 2 - 4 time diagrams of voltages on the oscilloscope screen.

The device (see Fig. 1) contains an alternating voltage generator 1, a resistor store 2 connected to an inductance store 3, a resistor store 4 connected to one of the terminals 5, 6 for connecting a turnable coil, double pole 7, 8 and two-way 9, 10 and 11, 12 switches. Its first pair of contacts 9, 11 is connected to the output poles of a constant voltage source 13, and the second pair of contacts 10,12 are short-circuited and connected to one of terminals 14, 15 exemplary coil 16. One input Measuring voltage: voltage 17 is connected to the common connection point of two magazin resistors 2f 4, and the other through a single pole switch 18 a three position 19, 20, 21 with a neutral position 20 connected to pins 19 and 21 to the output poles 9, 11 of the constant voltage source 13 Ferrosonde 22, mounted in the center of the model katut.11 and 16, is connected to the electronic unit of the magnetometer 23 and the external noise compensator 24. The signal input of the synchronous detector 25 is connected to the output of the electronic unit of the magnetometer 23, and its output is connected via an integrator 26 to the null indicator 27. The threshold device 28, whose input is connected to an alternating voltage generator 1 and the output to the control input of the synchronous detector 25. The oscilloscope 29 is connected to the output of the synchronous detector 25, the signal input of which is additionally connected by a jumper 30 to the output of the integrator 26. The generator The connected voltage 1 is connected to the common connection point of resistors 2.4 and to terminal 15 of the model coil 16.

The device works as follows.

Claims (1)

An exemplary coil 16 with a flux probe 22 is installed in the center of a rotatable one, which is connected to terminals 5, 6. The compensator 24 in the volume of the flux probe 22 compensates external magnetic fields to zero, which is controlled by zero - indicator 27. By means of a two-polar 7, 8 two positional 9, 10 and 11, 12 switches to the reference and test coil supply alternating current from generator 1. At the same time, the source of this voltage 13 is disconnected. By varying the resistance value of the resistor 2 and the inductance of the magazine. 3, the phase voltage is reduced to zero. nekompensirovan shift of magnetic fields 16 and exemplary and is believed emoy coils which included counter. At the same time, due to the additional connection of the synchronous detector 25 by jumper 30 to the output of the integrator 26 on the oscilloscope screen 29 of the semi-sine wave from the initial position (the curve in FIG. Takes a symmetrical position between the two fronts of the rectangular gating pulse of the pore device 28 (the curve in FIG. 3) After that, by varying the resistance of the resistor 4, the amplitudes of the synchronous magnetic fields in the coils are equalized, and the voltage diagram on the oscilloscope screen 29 will look almost straight line (see Fig. 4). 1 and I о in parallel branches x from resistor 2 with inductance store 3 and resistor 4 with a rotatable coil (connected to terminals b, 6) are in total equal to the current of exemplary cutter 16: I, + 1, S H 1 Ferrosonde 22 measures the difference of magnetic inductions l B in the center of the coil, which is reduced to zero with the above adjustments: ua - i3vVx- ° 2) where KO, K y, are fixed reference 16 and verified (connected to terminals 5, 6) coils. From expressions (1) and (2): x. if KO K. When KO K is sample 16 and verifiable (connected to terminals 5, 6), the coils are changed by months, and the calculation is carried out according to the formula: - Constant voltages Urt with a DC 17 gauge using a single pole 18 three-position switch 19, 20, 21, which is connected to the source of the constant voltage 13. In this case, all components of the active resistance of the chain are taken into account, and the accuracy of the measurements increases by about an order of magnitude. Thus, the use of the device makes it possible to increase the accuracy of calibration, approximately by an order of magnitude, by measuring stresses on all sections of the circuit. The invention The device for calibration of measures of magnetic induction on alternating current, ke, containing an exemplary coil installed inside a testable one, two resistors, an inductance store, an alternating voltage generator, a ferrosonde mounted in the center of the coils and an output connected to the electronic unit of the magnetometer, and input - to the external noise compensator, a synchronous detector, the signal input of which is connected to the output of the magnetometer, and its output is connected via an integrator to the null indicator, a threshold element, an input Some of them are connected to an alternating voltage generator, and the output is connected to a control input of a synchronous detector, a DC voltage meter and switches, which are powered by the fact that, in order to improve the accuracy, it is supplied with a constant voltage source the output of which through a pair of contacts of the first switch is connected to the terminals for connecting the turned coil directly. The second output is through the inductance store and two resistors, the second pair of contacts of the said switch is short-circuited connected via an exemplary coil to one of the outputs of the alternating voltage generator, the second output of which is connected to the common point of two resistor stores, to which one of the inputs of the constant voltage meter is also connected, the other input is through a unipolar three-position switch with a neutral position connected to the poles of a constant voltage source. Sources of information taken into account in the examination 1. Works of metrological institutes of the USSR. Energie, L., 1972, l. 140 (200), p. 89 92. 2, Works of metrological institutes of the USSR. Energie, L., 1975, no. 180 (240), p. 9 - 16. Figg FIG. Fng.)