SU1318958A1 - Measuring device for geoelectric surveying - Google Patents

Abstract

This invention relates to electrical survey. The aim of the invention is to improve the measurement accuracy. The device is equipped with a second block of transmission of a compensating signal, containing a series of work switch, a polarization compensator, a sensitivity switch and a modulator, and a key. 1 il. 00 00 con el 00

Description

The invention relates to the field of electrical prospecting and can be applied with vertical electrical sounding.

The aim of the invention is to increase the measurement accuracy. I

The essence of the invention is

in compensation of the signal coming from the measuring electrodes. Compensation is carried out using the signal coming from the power line. This makes it possible to significantly reduce the effect of interference due to the instability of the amount of current in the supply line. A polarization compensator is required to compensate for electrode polarization. A second modulator is needed to convert the DC signal from the measurement electrodes into a variable signal. The additional primary winding in the input transformer, which is not galvanically connected to the transformer windings, is necessary to eliminate the galvanic coupling between the signals coming from the supply line and the measuring electrodes.

The drawing shows a block diagram of the device.

The device contains a current source I, current recorder 2, shunt 3, supply line AB, key 4, work type switch 5 with inputs 5.1-5.4, measuring electrodes M and N, which are respectively connected to inputs 5.3 and 5.4 of switch 5 type of work, polarization compensator 6, sensitivity switch 7, modulator 8, input transformer 9 with two primary windings 9.1 and 9.2 and one secondary winding 9.3, attenuator 10, sensitivity regulator 11, modulator 12, variable-frequency amplifier 13, demodule torus 14, which, like modulators 8 and 12, works The recorder 16 melts from the generator.

. The device works as follows.

Preparation for work.

Turn on the key 4, turn off the power of the polarization compensator 6, and set the attenuator 10 to the zero position. and the switch 5 of the type of work is set to position 5.1 and 5.2. Further, the current source 1 through the supply line AB in the ground (or at the load) excites a constant field

-,

to

15

89582

(in the form of pulses of positive and negative polarities). Upon excitation, the field from shunt 3 removes the signal coming simultaneously to the switch of the 5 kind of work and the attenuator 10. Through the sensitivity switch 7 and the sensitivity monitor 1, the signals go to the corresponding modulators 8 and 12 and are modulated to high frequency alternating current pulses The primary windings 9.1 and 9.2 of the input transformer 9 are galvanically not connected to each other, where partial compensation takes place, since the signals from modulators 8 and 12 have opposite polarities.

Uncompensated part of the signal

20 from the secondary winding 9.3 of the transformer 9 is fed to the AC amplifier 13, then the signal is rectified by the demodulator 14 and fed to the recorder. 16. The modulators 8 and 12, as well as the demodulator 14, operate from a single oscillator 15 at the same frequency. Using the sensitivity controller 11, a zero value is set on the recorder 16 when the scientific research institute has a coarse sensitivity switch 7 sensitivity. Then gradually, the sensitivity switch 7 is switched to a more sensitive position and with the help of

35 of the sensitivity regulator 11 again set the zero value on the recorder 16. Thus, the signals received at both primary circuits of the input transformer 9 are fully compensated. The device is prepared for direct measurement.

45,

Measurement of value -.

The key 4 is turned off, the switch 5 is set to position III-IV, as a result of which the measuring electrodes M and N are connected to the compensation

50 to the torus 6 of polarization, with which the electrode polarization is compensated. The sensitivity switch 7 is set to the coarsest sensitivity. Gradually increase

5 sensitivity by the sensitivity switch 7, continue to compensate for the electrode polarization with the polarization compensator 6 until it is fully compensated. After this switch

The sensitivity sensor 7 is again set to coarse sensitivity and a current I is passed through the supply line AB to the ground with a value I measured by the current recorder 2, and the potential difference di from the measuring electrodes M and N is observed on the recorder 16. and from shunt 3 a compensating signal is fed to the attenuator 10, with which a zero indication is obtained on the recorder 16. Gradually increasing the sensitivity with the sensitivity switch 7, continue the compensation and, As the sensitivity increases, attenuator 10 is achieved with a zero reading on the recorder 16. Thus, the signal coming from the measuring electrons M and .N is compensated.

After that, the counter installed on the attenuator 10, remove the resistance value

R - R - J,

where uU is the potential difference between the measuring electrodes M and Ni

I - the current strength in the AB line. .

Next, calculate the value of the apparent

formula resistance

84

P-K- f.

where K is the installation factor.

F o rumula invention ni

A measuring device for geoelectromagnetic, containing a current source, a current recorder, a supply line, measuring electrodes and a shunt, to the terminals of which the first is connected

A compensating signal transmission unit containing a series-connected attenuator, a sensitivity regulator, a modulator, an input transformer, an amplifier, a demodulator, a recorder, characterized in that, in order to improve the measurement accuracy, it additionally contains a second compensating signal transfer unit, including

series of work switch, polarization compensator, sensitivity switch, modulator and key connected between one of the work switch switch inputs, the second switch input is connected to the second output of the shunt, the second input of the attenuator is connected to the key output, the third and fourth inputs the switch is connected to the measuring electrodes, and the transformer is provided with a second primary winding, to which the modulator output of the second transfer unit of the compensating signal is connected.

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9.3

15

Editor V.Danko

Compiled by E.Gorodnichev

Tehred M. Hodanich. Proofreader A.Zimokosov

Order 2507/40 Circulation 730 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

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Production and printing company, Uzhgorod, st. Project, 4

14

Claims (1)

Claim A geoelectrical exploration measuring device comprising a current source, a current recorder, a supply line, measuring electrodes and a shunt, to the terminals of which a first compensating signal transmission unit is connected, comprising an attenuator, a sensitivity regulator, a modulator, an input transformer, an amplifier, a demodulator, a registrar, different the fact that, in order to improve the accuracy of measurements, it further comprises a second transmission unit of the compensating signal, including connected in series a type of work switch, a polarization compensator, a sensitivity switch, a modulator and a key connected between one of the inputs of the type of work switch, the second input of the switch connected to the second output of the shunt, the second input of the attenuator connected to the output of the key, the third and fourth inputs of the switch connected with measuring electrodes, and the transformer is equipped with a second primary winding, to which the modulator output of the second compensation signal transmission unit is connected. Order 2507/40 Circulation 730 Subscription VNIIIPI of the USSR State Committee for Inventions and Discoveries 113035, Moscow, Zh-35, Raushskaya nab., D. 4/5 Production and printing company, Uzhhorod, st. Project, 4