SU960637A1 - Device for measuring complex conductance components - Google Patents

Description

(54) DEVICE FOR MEASURING COMPONENTS OF COMPLEX CONDUCTIVITY

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The image deviates from electrical measuring technology and can be used to measure electromagnetic characteristics.

A device is known for measuring the components of complex conductivity on T-shaped balanced bridges / containing a high-frequency voltage generator, an equilibrium indicator, connected respectively to the input and output of C, balanced single T-shaped bridge, whose transverse arm has parallel connected and inductance and two variable capacitor, one of which serves to balance the fj and the readout of the reactive component of the sample being measured, and the other being mated with a ladder eretlennoy containers in adjacent longitudinal aetf compensates for the change in the last 20 of the separate balancer variable capacitor serving; to balance and read the active component, and the capacitor is constant; ;

capacitance, located in the cich prvlegga: to him there are broader shoulders, h akvvno resistance, connected with a longitudinal branch parallel to the coaxial capacitors constant and interchange capacitance

The most common technical solution to the invention is a device for measuring components of complex conductivity that contains a single; T-shaped bridge, a first longitudinal shoulder which is formed reeistbrsml second Sh1echo - coil itsdukgnvvosTi, the transverse branch Moctti about azovava pervm kondensators 4 variable capacitor, a first output of which is connected (vrvym terminals of the resistor and coil ivduktivnostv / second output - to the total Shiva, reHepatxip eg high frequency switch, connected between the second end of the resistor in the busbar, equilibrium pointer, included: the second output of the KaTydiKH is inductive and has a second variable capacitor, the conclusions of which are with the second terminals of the 396063 resistor and conductor, terminals for connecting the measurement unit connected to the first and second terminals of the first variable capacitance capacitor G2. A disadvantage of the known device for measuring the js measurement components of the complex conductivity is the low measurement accuracy at high frequencies, since residual parasitic inductances in variable capacitors at high frequencies leads to an overestimation of the values of the capacitors of the capacitors, and thus, to the distortion of the main equation no measurement, The aim of the invention is to improve the accuracy of measurement of components of complex conductivity. This goal is achieved by the fact that the device for measuring the composition of the complex conductance contains a single T-shaped bridge, the first longitudinal arm of which is formed by a resistor, the second shoulder is formed by a coil and an inductor. The transverse branch of the bridge is formed by the first capacitor of variable s -capacity, the first output of which is connected to the first terminals of the resistor and the induction coil, the second output to the common bus, a high-frequency voltage generator connected between the second output of the resistor and the common bus, pointer equilibrium, connected between the second output of the inductor and the common bus, the second variable capacitor, the first output of which is connected to the second output of the resistor, terminals for connecting the object to be measured enes to first and second terminals of the first aromatic € nsagora variable capacitor, a variable inductance coil is introduced inductively associated meetings. but is connected with a coupling inductance, with the variable inductance coil being structurally coupled with the second variable capacitor and connected between the second terminals of the second capacitor and the inductor. Fig. I is a circuit diagram of an exemplary capacitor measure; Fig. 2 is a schematic diagram of the device. An exemplary low-loss variable capacitance capacitor I variable capacitance I can be represented as a substitute circuit consisting of primary capacitance 2, resistance 1sh 3 losses in dielectric, resistance 4 losses in conductive metal surfaces and inductance 5 electrodes of a co-capacitor 1. A capacitive effect known from the theory of inductively coupled elements (or the phenomenon of a false capacitance — negative inductance) was provided for this measure,

With a change in the capacitance of the capacitor of the variable capacitor, the value of the residual parasitic value of these elements changes; with the relative positioning of the moving and stationary electrodes of capacitor I, Coil 6 (L) and 7 (inductance connected to each other and with capacitor I in series, with coils 6 and 7 turned on and in close inductive relationship with each other. Coefficient K is defined by the expression -, - ° ... where M. is the mutual inductance of the coils, the value of the magnitude of the inductance of coil 6 is chosen from the condition / L-2Mhec, where 6s and the inductance of 5 electrons: s of capacitor I, ek 6 and 7 be such that, due to the magnitude of their mutual induction M in the circuit of the sample-conductance 5 of the electrodes of the capacitor L, t, e, the equilibrium condition (I) changes due to a change in its right-hand side. the left side of equation (I), for which the coil 6 is made variable. To do this at the same time, it is made constructively coupled with capacitor I, a device for measuring the complex conductivity (Fig 2) contains a high-frequency voltage generator 8, a capacitor 9 variable capacitance, used for balancing and counting the active component of the sample to be measured, resistor, capacitor 12 of variable capacitance, balancing and counting using reactive component, variable inductance coil 13, inductance coil 14 and equilibrium pointer 15, voltage from generator 8 goes to a T-shaped circuit consisting of coils 13 of variable inductance, resistor 11, inductor 14 and two capacitors 9 and 12, in which 5.9606 coil 13 is congruently associated with; a capacitor 9 and inductively coupled to the coil 14. Balance the circuit twice; be. formed by u and with the sample of y by means of capacitors 9 and 12, according to the zero-left indications of the indicator 15 of equilibrium. The data for the calculation of the reactive component are calculated by the limb of the capacitor 12, and the active component by the limb of the capacitor 9. The calculation is either the limbs of the capacitors 9 and 12, which in this case must be, o, 1, graded in certain units measurements, depending on the nature of the measured conductivity, or using t $ formulas. The inductor 13 only compensates for the inductance of 5 electrodes of the capacitor and in no way affects the equilibrium condition of the bridge, i.e. on the measurement process. In the proposed device for measuring the components of complex conductivity due to the specified circuit implementation of a single T-shaped bridge, 2 $ of the switching-on point of the compensating inductance combined with the chosen measurement method (by the method of two equilibrations), the influence of the parasitic inductance of the capacitor of the variable capacitor capacity when measuring the active component. at high frequencies.

Claims (2)

1. Kugaevsky A. F .. Measurement of parameters of ferromagnetic materials: at high frequencies, M., Publisher I standards, 1973, p. 97-98, fig. 48a, 2. USSR author's certificate number 842591, cl. GOi R 17/1 O, 1979 (prototype). 7 the longitudinal arm of which is formed by a resistor, the second arm by an inductor, the transverse branch of the bridge is formed by the first variable capacitor, the first output of which is connected to the first terminals of the resistor and inductance, the second terminal to the common bus, a high-frequency voltage generator turned on between the second output of the resistor and the common bus, equilibrium pointer, connected by the second output of the inductor and the common circuit, the second variable capacitor, the first output of which is connected to the second reziYchera th terminal, terminals for connecting the measuring object connected to the first and second terminals of the first variable capacitance capacitor, characterized in that, in order to increase the measuring accuracy, the device is introduced into a variable inductance coil, and inductively associated. oppositely connected to the inductance coil, the variable inductance coil being structurally coupled to the second variable capacitor and connected between the second terminals of the second capacitor and the inductance coil. Sources of information taken into account in the examination u -1-J.W / W: