SU938165A1

SU938165A1 - Bridge for measuring complex conductance components

Info

Publication number: SU938165A1
Application number: SU802960231A
Authority: SU
Inventors: Александр Федорович Кугаевский; Вячеслав Викторович Орехов
Original assignee: Рижский Краснознаменный Институт Инженеров Гражданской Авиации Им.Ленинского Комсомола
Priority date: 1980-07-11
Filing date: 1980-07-11
Publication date: 1982-06-23

Description

Изобретение относится к электро* измерительной технике, а точнее к измерениям комплексных величин и их параметров, и может быть использовано, например, в устройствах для измерения электромагнитных характерис- ⁵тик материалов на высоких частотах.The invention relates to electro * measurement technology, and more particularly to integrated measurement values and parameters, and can be used, for example, in devices for measuring electromagnetic charac- ⁵ tic materials at high frequencies.

Известны одинарные Т-образные уравновешиваемые мостовые схемы для измерения составляющих комплексного иммитанса образцов материалов и их параметров на высоких частотах, в которых активную составляющую измеряемого образца, а часто одновременно и реактивную составляющую, измеряют ₁₅либо по изменению величины переменного сопротивления, представляющего со- . бой многодекадный магазин активных проводимостей, либо по изменению величины переменного конденсатора, при-го чем схемы, в которых регулируемыми элементами являются только емкости, обладают гораздо большими возможностями, так как позволяют производить измерения на более высоких частотах и с меньшими погрешностями [1J.Single T-shaped balanced bridge circuits are known for measuring the components of the complex immittance of material samples and their parameters at high frequencies, in which the active component of the measured sample, and often at the same time the reactive component, is measured ₁₅ either by changing the value of the variable resistance, representing co. A multi-decade store of active conductivities, or by changing the value of a variable capacitor, moreover, circuits in which only capacitances are adjustable elements, have much greater capabilities, since they allow measurements at higher frequencies and with fewer errors [1J.

Недостаток этих схем - низкая точность измерений (особенно малых образцов материалов) на высоких частотах из-за.весомого влияния остаточных параметров элементов плеч, приводящая к необходимости введения поправок, определение которых с достаточной точностью представляет собой трудоемкую задачу, а на более высоких частотах вообще теряет какой-либо смысл.The disadvantage of these schemes is the low accuracy of measurements (especially of small samples of materials) at high frequencies due to the weighted influence of the residual parameters of the shoulder elements, which leads to the need to introduce corrections, the determination of which with sufficient accuracy is a laborious task, and generally loses at higher frequencies any meaning.

Наиболее близким по технической сущности является мост, имеющий генератор напряжения высокой частоты, указатель равновесия, одни выводы которых подключены к общей шине, и одинарную Т-образную схему, содержащую конденсатор переменной емкости, включенный в поперечное плечо, один вывод которого соединен с общей шиной, зажимы для подключения объекта измерения, расположенные параллельноThe closest in technical essence is a bridge having a high-frequency voltage generator, an equilibrium indicator, one of the terminals of which are connected to a common bus, and a single T-shaped circuit containing a variable capacitor included in the transverse arm, one terminal of which is connected to a common bus, clamps for connecting the measuring object located in parallel

938165 4 конденсатору переменной емкости, резистор, подсоединенный в первое продольное плечо одинарной Т-образной схемы, во второе^продольное плечо которой включена катушка индуктивности, причем один вывод резистора соедиОтсюда видно, что наличие сопротивления потерь катушки индуктивности приводит не только к искажению фиксации режима схемы, которому соответствует условие равновесия, но и к искажению основных уравнений, т.е. к ненен с вторым выводом указателя равновесия , а второй вывод резистора с вторым выводом первого конденсатора переменной емкости и с одним выводом катушки индуктивности, второй вывод которой соединен с вторым выводом генератора напряжения высокой частоты, и второй конденсатор переменной емкости, включенный параллельно резистору и катушке индуктивности продольной ветви [2].938165 4 to a capacitor of variable capacitance, a resistor connected to the first longitudinal arm of a single T-shaped circuit, the second ^ longitudinal arm of which is connected to an inductor, and one output of the resistor is connected. , which corresponds to the equilibrium condition, but also to the distortion of the basic equations, i.e. to nen with the second terminal of the equilibrium indicator, and the second terminal of the resistor with the second terminal of the first variable capacitor and one terminal of the inductor, the second terminal of which is connected to the second terminal of the high frequency voltage generator, and the second variable capacitor connected in parallel with the resistor and inductor longitudinal branches [2].

' Схема, используя подключение образца параллельно поперечному плечу, реализует метод двух уравновешиваний: при разомкнутых зажимах и при включении измеряемого объекта. Из условий равновесия моста без образца разцом имеем:'' The circuit, using the connection of the sample parallel to the transverse shoulder, implements the method of two balancing: with open clamps and with the inclusion of the measured object. From the equilibrium conditions of a bridge without a sample, we have:

1о cP где/^С^-Ц ς<ΐ)__οαΐ)1o cP where / ^ С ^ -Ц ς <ΐ) _ _ο αΐ)

т.е. стечет составляющих изм^Ьяемой проводимости осуществляется по изменению емкостей. Однако, уравнения измерения известного устройства существенно отличаются от (.1 ) и (2), если учесть остаточные параметры элементов плеч моста, причем, как показывает практика, наиболее существенное влияние на результаты измерений оказывают сопротивления потерь катушек индуктивности, поскольку добротность последних в несколько раз ниже, чем добротность конденсаторов. В этой связи окончательное условие равновесия известного устройства с учетом сопротивления потерь катушки индуктивности записывается как:those. The draining of the components of the variable conductivity is carried out by a change in capacitance. However, the measurement equations of the known device differ significantly from (.1) and (2), if we take into account the residual parameters of the elements of the bridge arms, and, as practice shows, the most significant influence on the measurement results is exerted by the loss resistance of the inductors, since the quality factor of the latter is several times lower than the quality factor of capacitors. In this regard, the final equilibrium condition of the known device, taking into account the loss resistance of the inductor, is written as:

I ^J В) (2 ) и с об10 откуда уравнение измерения (.1) и принимают вид (4) верному отсчету составляющих измеряемого образца; учет влияния сопротивления потерь катушки индуктивности с достаточной точностью в виде введения поправок затруднителен из-за их сложной зависимости как от частоты измерений, так и от изменения емкостей регулировочных конденсаторов. .I ^J B) (2) and with about 10 from where the measurement equation (.1) takes the form (4) for the correct reading of the components of the measured sample; It is difficult to take into account the influence of the loss resistance of the inductor with sufficient accuracy in the form of corrections because of their complex dependence both on the measurement frequency and on the change in capacitance of the regulating capacitors. .

Все это сказывается на точности измерений особенно малых величин образцов материалов на высоких частотах и является существенным недостатком известного устройства, ограничивающим его широкое применение.All this affects the accuracy of measurements of especially small values of samples of materials at high frequencies and is a significant drawback of the known device, limiting its widespread use.

Цель изобретения - повышение точности измерений комплексной проводимости особенно малых образцов материалов на высоких частотах одинарной Т-образной мостовой схемы с отсчетом составляющих по изменению емкостей.The purpose of the invention is to increase the accuracy of measurements of the complex conductivity of especially small samples of materials at high frequencies of a single T-shaped bridge circuit with a count of components for the change in capacitance.

Поставленная цель достигается тем, что в мосте измерения составляющих комплексной проводимости на высоких частотах, содержащем генератор напря( жения высокой частоты, указатель равновесия, первый вывод которого соединен с общей шиной, и одинарную Т-образную схему, состоящую из конденсатора переменной емкости, включенного в поперечное плечо, первый вывод которого подсоединен к общей шине, зажимов для подключения объектов измерения, включенных параллельно конденсатору переменной емкости, резистора, подключенного в первое продольное плечо одинарной Т-схемы, катушки индуктивности, включенной в другое продольное плечо, первый вывод которой соединен с одним выводом генератора напряжения высокой частоты, а второй вывод - с вторым выводом конденсатора переменной емкости и с одним выводом резистора, другой вывод которого подсоединен к второму выводу указателя равновесия, и второго конденсатора’ переменной емкости, включенного в продольную ветвь параллельно катушке индуктивности и резистору, параллельно поперечному плечу · подсоединен вход повторителя напряжения, выход которого вклюуен последовательно с генератором напряжения высокой частоты.This goal is achieved by the fact that in the bridge of measuring the components of complex conductivity at high frequencies, containing a high-frequency voltage generator, an equilibrium indicator, the first output of which is connected to a common bus, and a single T-shaped circuit consisting of a variable capacitor included in transverse arm, the first terminal of which is connected to a common bus, clamps for connecting measurement objects connected in parallel with a capacitor of variable capacitance, a resistor connected to the first longitudinal arm a single T-circuit, an inductor included in another longitudinal arm, the first terminal of which is connected to one terminal of a high-frequency voltage generator, and the second terminal is connected to the second terminal of a variable capacitor and one terminal of a resistor, the other terminal of which is connected to the second terminal equilibrium indicator, and a second capacitor 'of variable capacitance included in the longitudinal branch parallel to the inductor and resistor, parallel to the transverse shoulder · connected to the voltage follower output to The switch is switched on in series with a high-frequency voltage generator.

На чертеже приведена электрическая схема моста.The drawing shows the electrical circuit of the bridge.

Мост содержит генератор 1 напряжения высокой частоты, конденсатор 2 переменной емкости (С^), служащий для уравновешивания и отсчета по реактивной составляющей измеряемого образца, резистор 3 (R), катушку 4 индуктивности (L, г), конденсатор 5 переменной емкости, служащий для уравновешивания и отсчета по активной составляющей (С^), повторитель 6 напряжения (ПН) и индикатор 7, измеряемый эбъект 8.The bridge contains a high-frequency voltage generator 1, a capacitor 2 of variable capacitance (C ^), which serves to balance and read out the reactive component of the measured sample, a resistor 3 (R), an inductor 4 (L, g), a capacitor 5 of variable capacitance, which serves to balancing and counting by the active component (C ^), voltage follower 6 (PN) and indicator 7, measured object 8.

Напряжение от генератора 1 поступает на Т-образную цепь, состоящую из резистора 3, катушки 4 индуктивности и двух конденсаторов 2 и 5 переменной емкости. Вход ПН 6 подключается параллельно конденсатору 2 пере-20 менной емкости, а выход - последовательно с генератором 1 напряжений высокой частоты. Индикатор 7 баланса схемы включается на выход Т-образной |Цепи, а измеряемый объект 8 параллельно конденсатору 2 переменной емкости. Уравновешивают схему дважды: без образца, т.е. при жимах 9-9The voltage from the generator 1 is supplied to a T-shaped circuit, consisting of a resistor 3, an inductor 4 and two capacitors 2 and 5 of variable capacitance. The PN 6 input is connected in parallel to the variable capacitor 2, and the output is connected in series with the high-frequency voltage generator 1. The indicator 7 of the balance of the circuit is turned on at the output of the T-shaped | Circuit, and the measured object 8 is parallel to the capacitor 2 of variable capacity. Balance the circuit twice: without sample, i.e. with bench presses 9-9

т.е.those.

разомкнутых за( холостой ход), и с образцом, конденсаторами переменной ем-30 кости 2 й 5 по нулевым показаниям индикатора 7. Данные для расчета реактивной составляющей отсчитывают по Ьимбу конденсатора 5 переменной емкости, а расчет осуществляется либо с использованием формул, либо непосредственно по лимбам конденсаторов и 5, которые в этом случае должны быть отградуированы в определенных единицах измерения, в зависимости от характера измеряемой проводимости, другие структуузлом в немopen for (idling), and with the sample, capacitors of variable em-30 bones of the 2nd 5th according to the zero readings of indicator 7. The data for calculating the reactive component are measured by the capacitor 5 of the variable capacitance, and the calculation is carried out either using formulas or directly by capacitor limbs and 5, which in this case must be calibrated in certain units of measurement, depending on the nature of the measured conductivity, others in the structure of the node in it

Мост такого типа, как и Т-образные уравновешиваемые ры, относят к устройствам с уравновешивания токов, т.е.A bridge of this type, like T-shaped balanced rivals, is referred to devices with balancing currents, i.e.

происходит уравновешивание токов и 4· В момент равновесия, когда ток через индикатор 7 равен нулю, эти токи равны по величине и противоположны по фазе:currents are balanced with 4 · At the moment of equilibrium, when the current through indicator 7 is zero, these currents are equal in magnitude and opposite in phase:

ir -U (6)ir -U (6)

т.е. потенциал точки 10 индикатора моста оказывается равным потенциалу земли, что равносильно тому, что конденсатор 5 переменной емкости и резис-®$ тор 3 заземляются, причем последнее подключается параллельно конденсатору 2 переменной емкости на вход ПН 6.those. the potential of point 10 of the bridge indicator turns out to be equal to the potential of the earth, which is equivalent to the fact that the variable capacitor 5 and the resistor ® $ 3 are grounded, the latter being connected in parallel to the variable capacitor 2 to the PN 6 input.

Если при этом сопротивление резистора 3 и емкость конденсатора 2 . переменной емкости выбраны так, что для всех частот измерения выполняется неравенство (11 (что особенноIf at the same time the resistance of the resistor 3 and the capacitance of the capacitor 2. variable capacitance are chosen so that for all measurement frequencies the inequality (11 (which is especially

I малых t_K, прохарактерно для образцов материалов ), то ток текающий по катушке 4 индуктивности, замыкается, в основном, через сопротивление' резистора 3 (Дчс ΐ-ι ) » падение напряжения На котором через ПН 6 суммируется с напряжением питания моста. Напряжение на выходе ПН 6 определяется выражением:I small t _K , which is typical for samples of materials), then the current flowing through the inductor 4 closes mainly through the resistance of the resistor 3 (DCh ΐ -ι) ”voltage drop On which through PN 6 is summed with the supply voltage of the bridge. The voltage at the output of PN 6 is determined by the expression:

WW <8?WW <8?

а общее уравнение для напряжения цепи компенсации, при условии, что внутреннее сопротивление столько мало, чтб^г им с достаточно высокой ти, генератора наможно пренебречь степенью точноепринимает вид:a general equation for the voltage compensation circuit, provided that the internal resistance as little ^g chtb them with sufficiently high ti generator namozhno negligible degree tochnoeprinimaet form:

⁽⁹⁾ ύ₀ - напряжение генератора в'ысочастоты; К_п - коэффициент передагде кой чи ПН (0<Κ_π<Ί). ⁽⁹⁾ ύ ₀ - generator voltage at high frequency; To _p is the coefficient of redirectional PN (0 <Κ _π <Ί).

Подставив значение V_pH из уравнения (8, в (9), после некоторого преобразования определяем значение тока, протекающего в этой цепи, и условие компенсации активного сопротивления катушки индуктивностиSubstituting the value of V _pH from equation (8, in (9), after some transformation, we determine the value of the current flowing in this circuit and the condition for compensating the active resistance of the inductor

No (Ю) при (11) (12) ¢5 tip-u. h-K_MRNo (10) at (11) (12) ¢ 5 tip-u. hK _M R

Т Ц - jwk+R.T C - jwk + R.

При этом следует отметить, что ПН решает только отведенную ему узкоЬпециализированную задачу компенсаций активного сопротивления катушки индуктивности, поскольку обладает достаточно высоким входным и очень малым выходным сопротивлениями, что не позволяет ему практически оказывать сколь-либо заметное влияние на условие равновесия моста', т.е.' на процесс измерений.It should be noted that the PN solves only the narrowly specialized task of compensating the active resistance of the inductor, because it has a sufficiently high input and very small output resistances, which does not allow it to have any noticeable effect on the equilibrium condition of the bridge, i.e. . ' on the measurement process.

Условие равновесия одинарной Т-образной структурыEquilibrium condition for a single T-shaped structure

Wvw⁰ для схемы моста в случае, когда образец не подключен, а сопротивление потерь катушки 4 индуктивности скомпенсировано, запиеывается какWvw ⁰ for the bridge circuit in the case when the sample is not connected, and the loss resistance of the inductor 4 is compensated, it is sealed as

Если приравнять вещественные и мнигЗые части уравнения (13) к нулю, то окажется, что первоначальное уравновешивание моста достигается при равных значениях емкостей переменных конденсаторов с?= с?= i/(tt)4), что упрощает и повышает точность начальной настройки схемы и улучшает (14) ее сходимость.If we equate the real and minor parts of equation (13) to zero, then it turns out that the initial balancing of the bridge is achieved with equal capacitances of the variable capacitors with? = C? = I / (tt) 4), which simplifies and increases the accuracy of the initial setup of the circuit and improves (14) its convergence.

Для схемы моста в случае, когда образец подключен, уравнение равновесия принимает вид juu L (jwC f ) Ro-H wb + ^{+ Z}°'For the bridge circuit in the case when the sample is connected, the equilibrium equation takes the form juu L (jwC f) Ro-H wb + ^{+ Z} ° '

Взяв разность между 415) и '(43) , окончательное условие равновесия схемы в случае метода двух уравновешиваний получаем в виде:Taking the difference between 415) and '(43), the final condition for the equilibrium of the circuit in the case of the two balancing method is obtained in the form:

’ (16) пе &C,j , АС 2 изменение емкостей соответственно С^ и’(16) ne & C, j, AC 2 capacitance change respectively C ^ and

Cz, причем выражение (16),Cz, and expression (16),

т.е.those.

:ревнивая к нулю вещественные части, активную и реактивную ссс ''валяющие проводимости в этом слу отделяют из равенств;: jealous of the real parts to zero, the active and reactive scc '' fading conductivities in this case are separated from the equalities;

чально уравновешивается при равных значениях емкостей переменных конденсаторов; имеет раздельный баланс по активной и реактивной составляющим; в схеме моста регулируемый элемент и измеряемый объект заземлены, т.е. подключаются в поперечное плечо моста; и наконец, схема устраняет влияние рстаточного сопротивления потерь катушки индуктивности.It is essentially balanced at equal values of capacities of variable capacitors; has a separate balance between active and reactive components; in the bridge circuit, the adjustable element and the measured object are grounded, i.e. connected to the transverse shoulder of the bridge; and finally, the circuit eliminates the influence of the residual resistance of the inductance coil losses.

**

Claims

The invention relates to electrical measuring equipment, and more specifically to measurements of complex values and their parameters, and can be used, for example, in devices for measuring the electromagnetic characteristics of materials at high frequencies. Single T-shaped balanced bridge circuits are known for measuring the complex immittance components of material samples and their parameters at high frequencies, in which the active component of the sample being measured, and often simultaneously the reactive component, is measured either by a change in the value of the variable resistance representing a multi-decade store of active conductivities, or by changing the value of the variable capacitor, with circuits in which the regulated {elements are the capacitance, They are much more powerful because they allow measurements to be made at higher frequencies and with smaller errors lj. The disadvantage of these schemes is the low accuracy of measurements (especially of small samples of materials) at high frequencies due to the significant influence of the residual parameters of the elements of the arms, leading to the need for introducing corrections, the determination of which with sufficient accuracy is a time-consuming task, and for higher ones frequencies generally lose any meaning. The closest in technical essence is a bridge having a high-frequency voltage generator, an equilibrium indicator, some of whose outputs are connected to a common bus, and a single A T-shaped circuit containing a variable capacitor included in a transverse arm, one output of which is connected to a common bus, clamps for connecting a measurement object, arranged parallel to a variable capacitor, a resistor connected to the first longitudinal shoulder of a single T-shaped circuit, to the second the longitudinal arm of which includes an inductance coil, with one output of the resistor connected to the second output of the pointer equal to the balance, and the second output of the resistor with the second output of the first capacitor variable capacitance and with one output coil inductance, the second output of which is connected to the second output of the high-voltage generator, and the second variable capacitor connected in parallel to the resistor and inductance of the longitudinal branch 2, the circuit, using connecting the sample parallel to the transverse shoulder, implements the method of two balancing when the terminals are open and when the measured object is switched on. From the equilibrium conditions of a bridge without a sample and with a sample, we have: .yCcw-RbAC); / (LH-OyC, (H1) (4th (Cf) (.1). -Ci LS2 tx) with ttt) i.e. Flow of the components of the measurable conductivity is carried out by changing the capacitances. However, the equations for measuring a known device are significantly different from () and (2) if we take into account the residual parameters of the elements of the bridge shoulders, and, as practice shows, the loss resistance of the inductors has the most significant effect on the measurement results. several times lower than the quality factor of the capacitors. In this connection, the final equilibrium condition of the known device, taking into account the loss resistance of the inductance, is written as: P, -. (.) (Ru.) J; y where the measurement equation (.1) and C2 take the form g -,. 1 / | a, 4.c, V. () T (4. This shows that the presence of loss resistance of an inductor leads not only to a distortion of the fixation of the circuit mode, which corresponds to the equilibrium condition, but also to a distortion of the basic equations, i.e. incorrect measurement of the components of the sample to be measured; taking into account the effect of the loss resistance of the inductor with a sufficient Accuracy in the form of introducing corrections is difficult because of their complex dependence on both the measurement frequency and the change in the capacitances of the adjustment capacitors. All this affects the accuracy of measurements of especially small samples of materials at high frequencies and is a significant disadvantage of the known device, limiting its wide application. The purpose of the invention is to improve the accuracy of measurements of the complex conductivity of especially small samples of materials at high frequencies of a single T-shaped bridge circuit s with a count of components to change tanks. The goal is achieved by the fact that in a bridge, measurements of components of complex conductivity at high frequencies, containing a high-frequency voltage generator, an equilibrium indicator, the first terminal of which is connected to a common busbar, and a single T-shaped circuit consisting of a variable capacitor, connected to the transverse arm, the first output of which is connected to the common bus, clamps for connecting measurement objects connected in parallel with a variable capacitor, a resistor connected longitudinally to the first a single T-circuit arm, an inductance coil connected to another longitudinal arm, the first output of which is connected to one output of a high-frequency voltage generator, and the second output - to a second output of a variable capacitor and one output of a resistor, the other output of which is connected to the second output of the equilibrium indicator, and the second variable capacitor connected in the longitudinal branch parallel to the inductor and the resistor, parallel to the transverse arm are connected the input of the voltage follower, vklyuuen which move successively from the voltage generator of high frequency. The drawing shows the electrical circuit of the bridge. The bridge contains a high-frequency voltage generator 1, a variable capacitor 2 (C), which serves to balance and read the reactive component of the sample being measured, resistor 3 (R), inductance coil k (L, g), variable capacitor 5 used for balancing and counting by the active component (C., voltage follower 6 (PN) and indicator 7, measured by an object 8. Voltage from generator 1 is connected to the T-shaped circuit consisting of resistor 3 , inductors and two capacitors 2 and 5 of variable capacitance. The PN 6 is connected parallel to the capacitor 2 of the variable capacitance, and the output is connected in series with the high-frequency voltage generator 1. The balance indicator 7 switches on the output of the T-shaped circuit and the measured object 8 is parallel to the variable capacitor 2. The circuit is balanced twice: without a sample, i.e. with the presses 9-9 open (idle), and with the sample, variable capacitors 2 and 5 according to zero indicator 7. The data for calculating the reactive component is measured using / imbu capacitor 5 variable capacitance and, and the calculation is carried out either using the formulas, or directly on the limbs of the capacitors and 5, which in this case must be calibrated in certain units of measurement, depending on the nature of the measured conductivity. A bridge of this type, like other T-shaped balanced structures, refers to devices with a current balancing node, i.e. it balances the currents T and 12. At the moment of equilibrium, when the current through the indicator 7 is zero, these currents are equal in magnitude and are opposite in Oase: 1, -1a, (6) i.e. the potential of point 10 of the bridge indicator is equal to the ground potential, which is equivalent to the fact that the variable capacitor 5 and the resistor 3 are grounded, the latter being connected parallel to the variable capacitor 2 at the input of the PN 6 If the resistance of the resistor 3 and the capacitor 2 are at the same time. variable capacitance is chosen so that for all measurement frequencies the inequality is fulfilled (which is especially characteristic of small samples of materials), then the current t flowing through the inductor coils is closed mainly through the resistance of the resistor 3 Cifc I-) the voltage drop which through PN 6 is summed with the supply voltage of the bridge. The voltage at the output of the PN 6 is defined by the expression: (8 and the general equation for the voltage of the compensation circuit, provided that the internal resistance of the generator is so small that it can be neglected with a sufficiently high degree of accuracy, takes the form: where GO is the voltage high frequency generator; K is the PI transfer coefficient (. Substituting the value of V from equation (8 / into (9), after some conversion, we determine the value of the current flowing in this circuit and the compensation condition of the active resistance of the inductance k of the circuit ju} b) il - -i viR- tUTu. GK QY. Vo J- / t -. It should be noted that the PH solves only the narrowly specialized task assigned to it to compensate the active resistance of the inductance, since it has a sufficiently high input and very low output resistance, which does not allow it to practically a noticeable effect on the equilibrium condition of the bridge, i.e., on the measurement process. The equilibrium condition of a single T-shaped structure for the bridge circuit in the case where the sample is not connected, and the resistance for loss of the inductance k th e is recorded as a jty Ljujc ;; R.-j jyu-vR. 0 (13 jCyCa I) If the real and lnium parts of equation (13) are equated to zero, then the initial balancing of the bridge will be achieved with equal values of the capacitances of variable capacitors C 1 / (OIF (1), which simplifies and improves the accuracy of the initial adjusting the circuit and improving its convergence. For the bridge circuit, when the sample is connected, the equation of equilibrium Si takes the form C) ja; U (ju c; Ver - jb) Ro4-jWU4 l :) 1 Bz into the difference between C15) and NC the final equilibrium condition of the scheme | In the case of the method of two balancing we obtain in the form. j Li: jcyuCi + g.) R. jO-uC-L LS — changes in capacitances, respectively, C.f and. r –c 1 g 1 with C. С 41 3L - i g ;; scratch for the expression (16, i.e., real i is equal to zero, v .-: m (–VT parts, active and reactive links) in this case, LL :: g, is divided from, equalities; R.I./SIL or SSC.); b - CG; dSn. Thus, the proposed scheme my ia allows you to measure the components of the complex conductivity containers, it contains the minimum number of elements necessary for equilibration and a separate reading of the conductivity components of the sample being measured; it is initially balanced with equal values capacities of variable capacitors; has a separate balance of active and reactive components; in the bridge circuit, the adjustable element and the measured object are grounded, i.e. connected to the transverse arm of the bridge, and finally, the circuit eliminates the effect of the inductance loss of the coil A bridge for measuring components of complex conductivity at high frequencies, comprising a high-frequency voltage generator, an equilibrium indicator, the first terminal of which is connected to a common bus, and a single T-o A phased circuit consisting of a variable capacitor included in a transverse arm, the first input of which is connected to a common bus, clamps for connecting a measurement object connected in parallel with a variable capacitor, a resistor connected to one longitudinal arm of the T-circuit, an inductor connected to another longitudinal arm, the first output of which is connected to one output of a high-frequency voltage generator, and the second output to a second output of a variable capacitor and to one output of a resistor a, another terminal of which is connected to a second terminal of the equilibrium indicator, and a second variable capacitor connected in a longitudinal branch parallel to a resistor and inductance coil, characterized in that, in order to improve measurement accuracy, a voltage follower input is connected parallel to the transverse arm, connected in series with a high frequency voltage generator. Sources of information taken into account in the examination 1, A. Kugaevsky. Measurement of parameters of ferromagnetic materials at high frequencies. M., ed. Standards, 1973, p. 90-105.

2. Authors certificate of the USSR on the application f 2909 39 / 18-21, 17.0.80 ((prototype).