SU924616A1 - Cg-type two-terminal network conductance component automatic meter - Google Patents

Description

 The invention relates to a measuring technique. It is intended to measure the equivalent parameters of a CG two-terminal device with large losses and can be used in the systems of dielectric monitoring of technological parameters of dispersed materials and substances with increased conductivity.

 A device for converting complex conductivity parameters is known comprising an AC source connected via a complex conductivity converting unit to an AC signal and an adder to a first output terminal of the device, which is connected to an adder through a phase-sensitive indicator and an adjustable gain unit. , stability and expansion of the working frequency range, a phase shifter and a block with a gear ratio, n oportsionalnym frequency 11,

The disadvantages of this device are one-parameter output and low speed.

Closest to the offer is an automatic meter

the conductivity component of a CG-two-terminal device, comprising a high-frequency oscillator, the first output of which is connected to an input measuring circuit, a decoder c. balanced amplifier control units. active conductivity and capacitance, a controlled capacitor connecting the output of the measuring circuit with the total

10 bus modulating capacitor connected to the common bus through the key 12,

The disadvantages of the known device are the nonlinearity of the transfer function of the channel for measuring the active conductivity in the region of high and low conductivities and the average response due to the use of a balanced amplifier in the decoder,

20

The purpose of the invention is to improve the speed and linearization of the transfer function of the active conductivity measurement.

The goal is achieved by

Claims (2)

25 that the automatic conductivity component meter of a CG-two-port device, comprising a generator of high-frequency oscillations, connected to the input of the measuring circuit, made in the form of parallel-connected inductors, a controlled capacitor and a circuit of successively connected modulating capacitor, and a key, and with one of the clamps to connect the monitored CG-two-pole, the other clamp is connected to the common bus meter, as well as blocks for monitoring the active conductivity and capacitance, introduced s are a synchronous detector, a phase shifter, a measuring amplifier, a dynamic tracking unit, and a perilynte 1 attenuator; the dynamic tracking unit, the first output of the latter is connected to the control output of the controlled capacitor, the second output is connected to the capacity control unit, and the third output is connected to the control input of the key, and the middle output of the key and the modulating capacitor is connected to the input of an adjustable attenuator, which is connected in parallel from a 1-loop circuit. The drawing shows a functional electrical system with: a device. The CG-two-pole automatic conductivity component meter contains a generator of 1 high-frequency oscillations, a measuring circuit 2 including an inductor 3, a controlled capacitor 4, a modulating capacitor 5, a switch 6, a controlled attenuator 7, a controlled two-pole O, synchronous generator 9 , measuring amplifier 10, dynamic tracking unit 11, blocks 12 and 13 of the control of active conductivity and capacitance, phase shifter 14. The output of measuring circuit 2 is connected to the first input of synchronous detector 9 and through a damped attenuator 7, the control input of which is connected to the modulating capacitor 5 and the switch b, with the common bus. The second output of the generator 1 high-frequency oscillations is connected through the phase shifter 14 with the second input of the synchronous detector 9; the output of the latter is connected via the measuring amplifier 10 with the block 12 of the control of active conductivity and the input of the block 1 of dynamic tracking. The first output of the dynamic tracking unit 11 is connected to the control input of the controlled capacitor 4, the second to the capacity control unit 13, and the third to the control input of the key 6. The device works in the following way. The high frequency signal from the high-frequency oscillator 1 through measuring circuit 2 passes to the first input of the synchronous detector 9. When the key is alternately closed with 6 command pulses from the output of the dynamic tracking unit 11, the operating point moves along the resonant characteristic of the circuit and the high-frequency voltage supplied to the input of the synchronous detector 9, is amplitude modulated. The envelope of this voltage from the output of the synchronous detector 9 is fed through the amplifier 10 to the input of the 11th tracker unit, where it is converted into a control voltage. This voltage is fed to the control input of the controlled capacitor 4 and changes its capacitance so that the modulation depth of the output voltage of the measuring circuit 2 decreases to zero. Since the control voltage on the controlled capacitor 4 is proportional to the measured capacitance, in the dynamic tracking unit 11, this voltage is converted to the signal C, which is further input to the capacitance control unit 13 and displayed. The output voltage of the synchronous detector 9 in the equilibrium state is proportional to the active conductivity, therefore, after amplification in the measuring amplifier 10, it is inputted as a signal C to the input of the active conductivity monitoring unit 12 and also displayed. However, due to the nonlinearity of the transfer function of the amplitude amplitude detector at low voltages at the input, the active conductivity conversion function would be nonlinear with large conductivities. To eliminate this drawback, an additional signal is introduced from the oscillator 1 of high-frequency oscillations to the synchronous detector 9, the phase of which is shifted by 180 ° with respect to the phase of the signal from measuring circuit 2. The phase of the output signal of measuring circuit 2 is in equilibrium state 4 const , the phase-amplitude characteristic of the phase shifter 14 is fixed. The reference voltage supplied to the second input of the synchronous detector 9 transfers it to the linear detection mode, the noaTONiy transfer function of the G channel is linearized. The nonlinearity of the transfer function of the channel G in the region of low conductivities is usually due to the asymmetry of the forms of the resonant characteristics of the measuring circuit 2 in the closed and open positions of the key. This asymmetry is due to the non-zero transient resistance of the closed key b, which leads to a decrease in the quality factor of measuring circuit 2. To balance these characteristics parallel to measuring circuit 2, an adjustable regulator 7 is turned on, whose resistance changes in the process of switching key 6 so that the quality factor is measured circuit 2 remains the same. The invention The automatic conductivity meter CG-bipolar containing a generator of high-frequency oscillations, connected to the input of the measuring circuit, made in the form of parallel-connected coil1 and inductance, controlled by a capacitor circuit of a series-connected modulating capacitor and key, and one of the terminals for connecting a controlled CG two-port network, another terminal is connected to the common bus meter, as well as blocks for controlling active conductivity and capacitance, characterized in that in order to increase speed and linearization of the transfer function of the active conduction measurement channel, a synchronous detector, a phaser, a measuring amplifier, a dynamic tracking unit and an adjustable attenuator are introduced into it, and the inputs of the synchronous detector are connected to the output of the high-frequency oscillator directly and through the phase rotator , the output of the synchronous detector through the measuring amplifier is connected to the active conductivity control unit and to the first input of the dynamic unit First tracking of the last output is connected to the control output of the controlled capacitor, the second output is connected to the capacitance control unit, and the third output is connected to the control input of the key, and the middle output of the key and modulating capacitor is connected to the input of an adjustable attenuator that is connected in parallel measuring contour. Sources of information taken into account during the examination 1. USSR author's certificate No. 572723, cl. G 01 R 27/02, 06.08,75, 2. Author's certificate of SSSG No. 661409, cl. G 01 R 27/00, G 01 R 27/26, 01.02.77.