SU1651238A1 - Device for measuring parameters of dielectric materials - Google Patents

Abstract

The invention relates to measurement technology and can be used in experimental physics. The aim of the invention is to improve the measurement accuracy with fast-flowing external influences on the investigated pielectric, the meter contains a generator 1, a resonator 2, bpoc 3, recorder h, a control unit including a converter 5, comparator 6, register 7, circuit 8, counter 9 variable voltage generator, including keys 10 and 11, counter 12, converter 13, controlled clock generator, including pulse generator 14 and divider 15, frequency meter 16. Introduction of the control unit, as well as generation torus clock generator and mutable voltage controllable allows to create conductive trace controllable feedback controlled oscillator 1. 3 ZP f-ly, 1 ill.

Description

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The invention relates to a measurement technique and can be used in experimental physics, in particular to study the parameters of dielectrics and plasma in studying the effects of fast-flowing external influences.

The purpose of the invention is to improve the measurement accuracy in fast-flowing external influences on the dielectric under study.

The drawing shows a structural electrical circuit for measuring parameters of dielectric materials.

The dielectric material parameter meter contains a microwave 1 generator, a measuring resonator 2 a measurement unit 3, a recorder 4, a control unit including a digital-analog converter 5, a comparator b, a serial shift register 7, a coincidence circuit 8, a counter 9, a variable voltage generator, including the first 10 and second 11 keys, a reversible counter 125 digital-analog converter 13, a controlled clock generator, including a generator of 14 pulses and a frequency divider 15, often a tomer 16,

The output of the generator 1 is connected in series with the resonator 2, the measurement unit and the recorder 4, the control unit, the generator of the varying voltage, the control input of the microwave generator 1 are connected in series to the first output of the measurement unit 3. The second output of the measurement unit 3 under

keys to controlled generator

synchronizing pulses, the output of which is connected to the control unit and the generator of the varying voltage. The output of the microwave generator 1 through the frequency meter 16 is connected to the second input of the measurement unit 3, and the output of the measuring resonator is connected to the second input of the control unit.

The control unit is configured as a serially connected second digital-to-analog converter 5, a comparator 6, a serial shift register 7, a coincidence circuit 8, and a counter 9.

The alternating voltage generator is designed as a series-connected digital-analog converter 13, a reversible counter

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12, keys 10 and 11, connected one parallel to another. At the input of the keys 10 and 11 from the counter 9, the opposite level voltages are supplied, ensuring their alternate operation. The keys 10 and 11 also receive synchronizing pulses from the controlled generator of synchronizing pulses. The key 10 is connected to the summing input of the reversible counter 12, and the key 11 is connected to the subtracting one. The digital code from the reversible counter 12 is fed to the digital-to-analog converter 13, the output voltage of which controls the frequency of the microwave generator 1. The controlled clock generator is made in the form of serially-connected pulse generator 14 and the digital-controlled frequency divider 15. Measuring parameters of dielectric materials works as follows. The microwave signal from the generator 1 is fed to the measuring resonator 2 and the frequency meter 16. From the output of these blocks, signals proportional to the transfer coefficient function of the resonator 2 from the frequency N (f) are fed to the input of the measuring unit 3, in which the shift of the maximum of the resonance curve is determined sample material, and the change in the coefficient of transfer determines the material tg Information about Ј and tg Ј of the sample is fed to the recorder 4 (where is dielectric constant, tg is the loss tangent).

The microwave generator 1, controlled by a variable voltage generator, is rebuilt in the range of variation of the transmission coefficient of the measuring resonator 2. For tracking the position of the resonant curve, feedback is realized, including a series-connected control unit, a variable voltage generator, a microwave 1 generator, and measuring resonator 2.

The control of the feedback feedback is carried out as follows. The sweep rate of the oscillator 1 frequency of the microwave controls the CHI-cal, arriving at the generator input of the varying voltage from the controlled clock generator, which, in turn, is controlled by a digital code proportional to the change in in time

and coming from the second output of the measuring unit.

From the first output of the measurement unit 3, a digital code proportional to tgo and determining the threshold level are fed to the control unit for comparison with the signal at the output of the measuring resonator 2, determine the amplitude of the voltage variation at the output of the alternating voltage generator,

The digital code received from the first output of the measurement unit 3 in the digital-to-analogue converter 5 is converted into a voltage that sets the reference level of the operation of the comparator 6, which compares it with the voltage at the output of the measuring resonator 2. excess of voltage from the output of the measuring resonator and zero at its low level.

The sequential shift register 7 and the coincidence circuit 8 are made so that the tracking system captures when dialing a specific digital code in register 7 that matches the previously established coincidence circuit 8. When the coincidence circuit 8 is triggered, the counter 9 is supplied with a unit level that changes its state to the opposite.

The frequency of the synchronizing pulses is controlled from measurement unit 3. With an increase in tg $ of the sample material, the transfer coefficient of the measuring resonator 2 decreases and its Q factor decreases, which leads to the need to lower the threshold level.

A change in Ј of the material leads to a shift of the resonant frequency of the measuring resonator 2. With a fast-flowing external effect on the sample material, a change of 6, and hence the resonant frequency can be tracked only if the speed of the initial data set in the form of N (f) increases that in this meter is realized by controlling the frequency of the clock pulses.

Experimental studies of dielectric properties tester

materials showed that, in comparison with the known devices, the proposed meter provides an increase in the speed and accuracy of determining 6 and ego materials by the resonance method in studying the effects of materials on high-speed external influences on the materials. For example, the use of this meter allows measuring the dielectric properties of materials under external influence of a change in heating temperature at a speed of 1000 K / min and accuracy of determination by B 3%, and by tg Ј 20%.

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Claims (4)

1, A dielectric materials parameter meter comprising a microwave generator, the output of which is sequentially connected to the measuring resonator, measuring unit and recorder, a frequency meter whose input is connected to the output of the microwave generator, and the output to the second input of the measuring unit, clock generator and variable oscillator voltages connected in series, characterized in that, in order to improve the measurement accuracy during high-speed external influences on the dielectric materials under investigation a control unit is inserted, and a clock pulse generator and a variable voltage generator are controllable, the first input of the control unit is connected to the first input of the measuring unit, its second input is connected to the output of the measuring resonator, the third input is connected to the output of the generator of synchronizing pulses, the fourth and the fifth inputs of the control unit are respectively the inputs for the signals. Setting the code and the initial installation, the first and second outputs of the control unit, respectively, are connected to the second and third inputs of the variable voltage generator, the output of which is connected to the control input of the microwave generator, and the control input of the clock generator is connected to the second output of the measurement unit. 2. The device according to claim 1, of which the control unit contains serially connected digital-analog converter, comparator, serial shift register, coincidence circuit, counter, the first input of the control unit is connected to the input of the digital-analog converter, the second input is connected to the second input of the comparator, the third input is connected to the second input of the serial shift register, the fourth input is connected to the second input of the coincidence circuit, the fifth input is connected to the second input of the counter, and the first and second you his moves are connected respectively with the first and second outputs of the counter. 3. The device according to p. Which differs in that the generator of the varying voltage contains first and second keys, the outputs of which are respectively connected to the first five 0 vym and second inputs of the reversible counter, the output of which is serially connected to a digital-to-analog converter, the first and second inputs of a variable voltage generator connected to the first and second inputs of the first and second keys, respectively, and its output is connected to the output of the digital-analog converter. 4. The device according to claim 1, characterized in that the controlled clock pulse generator comprises a pulse generator and a frequency divider connected in series, the input of the controlled clock pulse generator connected to the second frequency splitter input, its output to the frequency splitter output .