SU1449932A1 - Conductivity standard - Google Patents

Abstract

The invention relates to electrical measuring equipment and can be used, for example, for checking the conductivity of ac bridges. The purpose of the invention is to improve the accuracy and expand the range of reproducible values of conductivity. The measure includes a housing 5, current terminals 2 and 3, resistors 1 and a differential capacitor 4, consisting of three coaxially arranged stator electrodes (ESS). Outdoor SE P connected through a resistor 1 with a pin 2 measures. The internal ESS 10 is connected to another terminal 3. Two rotor electrodes (OM) 7 and 8 are fixed on the axis with a rotation of 180 °. relative to each other . RE 7 is located between the internal SE 10 and the onboard SE 11, the RE 8 between the SE 10 and the E 12. The differential capacitor – RE 6, mounted on the axis coaxially with the RE 7 and placed between the case and the CE 11, is inserted. In this case, the external SE 12 is connected to the first pin 2 of the measure. In addition, the ER 9 is inserted into the differential capacitor, fixed on an axis coaxially with the ER 7 and placed between the housing and the outer solar cell 12. The conductivity of the measure is proportional to the angle of rotation of the axis of the differential capacitor, the conductivity reading starts with zero. 2 Il. ;

Description

torus 4, placed in a shield shielding core 20, the measure scheme is

5, the Differential Capacitor consists of four rotor electrodes of the third 6, first 7, second 8 and fourth 9 made in the form of semicircular plates, of which the inner rotor electrodes 7 and 8 are main, and the outer rotor electrodes 6 and 9 are additional, and three stator electrodes: internal 10, connected to the first current output 2, first external, connected to the second current output 3 via one of the resistors 1, and the second external 12, connected directly to the second current output 3. The stator electrodes 10-12 are mounted coaxially on the housing plate 13 using insulators and racks 14. The rotor electrodes 6-9 are mounted 1 on the axis 15 and through it are electrically connected to the housing B and the rotor electrodes 7 and 8 are fixed with rotation by 180 ° relative to each other other and are located symmetrically in the gap between the stator electrodes 10 - 12. Additional rotor electrodes 6 and 9 are fixed coaxially with rotor 1-1 and electrodes 8 and 7, respectively, and are placed with the possibility of axial movement: the third rotor electrode 6 between body 5 and stationary torus electrode 11, the fourth rotor electrode 9 between the stator electrode I2 and the plate 13.

The stator electrodes 10 and P, together with the rotor electrode 7 and the standing electrodes 10 and 12, together with the rotor electrode B, form two differentially connected terminals.

a tripolar, which pass-through parameters on current leads are; 3 are defined at ,, I.elections

G U RC, (C, +

€ 4) - Kcf; (2)

YY

Cr

const.

where q is the angle of rotation of the axis of the rotor electrodes, proportional to the capacitance K, the value is constant.

The measure of conductivity works as follows.

In the initial position, the rotor electrode 7 closes the gap between the stator electrodes 10 and 11, therefore the capacitance C, and hence the conductivity of the measure, is equal to zero. By rotating the axis 15, the output of the rotor electrode 7 leads to an increase in capacitance (bone C. At the same time, capacitance C decreases. Between electrodes 7 and 11, and this decrease is always greater than the increase in capacitance C, since the gap between electrodes 10 and 11 is the presence of an electrode 7 in it is always greater than the gap between the electrodes 7 and 11. This unequal change in capacitances C and Cj is compensated by an increase in capacitance

C., due to the simultaneous movement of the electrode 6 in such a way that condition (i) is fulfilled. Removal of the electrode 7 is accompanied by the introduction of the electrode 8 into the space between the electrodes 10 and 12, which leads to a decrease in capacitance C to keep the main capacitance on the terminals of the measure% unchanged.

The change in the side output capacitor 3 capacitance (i.e., the capacitance of the current output 3 to the housing), which occurs when electrode 8 is displaced relative to electrode 12. The side capacitance of the output terminal 2 is provided by a symmetric gap between the electrode 10 and each of the electrodes

7 and 8. Plate 13 with posts 14 provides mechanical separation of the sta- tion. tarny electrodes relative to the housing 5.

Compliance with condition (1) in the presence of a resistor 1 makes it possible to obtain a linear dependence of the conductivity of the measure on the angle of rotation of the axis of the rotor electrodes in accordance with formula (2).

The proposed measure can also be used to obtain conductivities corresponding to tgS 0.1

In this case, the value of C, in formulas (2) and (3), should be divided by the coefficient (), but this somewhat violates the linearity of the scale of the measure.

The proposed measure improves the accuracy of reproduction of conductivity not less than 2 times, expands the range of reproducible value by 10-20 times. Improving the accuracy of the measure contributes to the constancy of its side containers. When calibrating transformat bridges, this provides a constant load on the transformer arms and facilitates the introduction of an amendment. When calibrating bridges with a balancing branch, the measurement time

0

five

five

0

five

reduced by half, as there is no need to adjust the balancing branch,

"

Claims (1)

Invention Formula A measure of conductivity, containing a body, current terminals, a resistor and a differential capacitor, consisting of three coaxially arranged stator electrodes, of which the first external stator electrode is connected through a resistor to the first current electrode, and the internal stator electrode is connected to the second current electrode, and two rotary electrodes mounted on an axis with a 180 ° rotation one relative to the other, one of which is located between the inner and first outer stator electrode, and the second between the inner and second stator electrodes, characterized in that, in order to increase accuracy and expand the range of reproducible values of conductivity, it is additionally equipped with a third rotor and fourth rotor electrodes, the third rotor electrode being fixed on an axis coaxially with the second rotor electrode and placed between the housing and the first external electrode the stator electrode, the fourth rotor electrode is fixed on the axis coaxially with the first rotor electrode and placed between the housing and the second external stator electrode, while the second electrode The outer stator electrode is connected to the first current measure module. /  iii Lk dag X FI.2