SU1408381A1 - D.c. standard potentiometer - Google Patents

Abstract

The invention relates to the field of electrical measuring equipment and can be used to create devices for checking notiometers of high accuracy classes. The invention makes it possible to increase the measurement accuracy by eliminating the error of the medium temperature, eliminating the random errors of individual resistors due to averaging. The device contains a current stabilization unit 1, a setting resistor 2, a block 3 of a decade switch, a 4-7 measuring decade resistors, a block of 8 reference resistor, 9-11 current ramifications, resistors 12-15, a switch 16 limits, contact elements 17-22, measuring value clips 23, and measuring decade taps 24 and 25 connected to the decade switch unit. The device also allowed him to reduce the instability of readings and correct the readings of the second and third measurement limits 1 sludge.

Description

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with;

The invention relates to the field of electrical measuring equipment and can be used to create devices for checking potentiometers of high accuracy classes.

The purpose of the invention is to improve the accuracy and measurement by eliminating the error of the ambient temperature, eliminating

ray errors of individual resisors due to averaging.

The drawing shows the functionality of: - a potentiometer circuit.

The potentiometer consists of a current stabilization unit 1 with rheostats, fed from a network, connected by one of the poles to the bottom of the installation resistor, and 2, the second output of which and the other pole of the current stabilization unit are connected to the unit: a decade switch connected with resistor outlets 4-7 measuring () decade, made according to an annular measuring circuit and containing a block of 8 support- 1 () resistors, consisting of several lines with a pos; It is connected with rehistoris and with branching tots: s 9-11. In one of the circuits, there are half a dozen. Pin-coupling resistors 12-5, with which the limit switch 16 is electrically connected by means of contacts 17-21, and contact 22 - with one of the branches of the current the source, and with the help of half-rings, with the quotes of 23 measuring values, from which the compensating voltage comes, the mercury leads 24 and 25 of the measuring resistors connected to the decade switch unit.

The heatpimeter works as follows.

Current I from one of the poles of block 1 of sta- tioning the current with rheostats passes through one of the circuits of block 3 of the ten-day switch, from which it falls depending on the position number to one of the outlets from the |) resistors from. of the measuring decade, for example, to tap 24 soils of resistors 5. In iiiecTe of connection 24 of the tap with a measuring circuit () of the decade, current I is divided into two ways - current li, pass n; iy through all resistors 5, and current 1d, passing shii through resistors 4i through block 8 of the reference resistor iji through resistors 7 and 6. In the place of connection tim ftvoda 25 decade measuring currents iH i 1 are merged into a single current It + Ii I Ftvod 25 and through current goes back to block 3 of decade switch, from which returns to the other pole of the stabilization unit 1 t () Ka with rheostats. Nominal resistances of resistors 4-7 of the measuring decade and resistors of the block 8 of the reference resistor. (with the exception of resistors 12-14) are the same and equal to 100 ohms. Resistance re-: HicTOpoB 12-14 are equal respectively to 101.

five

five

9 and 90 ohms, so that the total resistance of the resistors 12-15 is 300 ohms, not different from the sum of other resistors of the parallel resistor block 8, the resistance of which between the peaks of the 9 and 11 current branches is 100 ohms, and the voltage between them is 100 gV (the first measurement limit of the ring circuit).

Walk through the top of the fork 9

0 current, block C is divided into three equal parts by 1g / 3A, and at the top of the branching 10 currents, one of these parts is divided into three equal parts by 1g / 9A. Therefore, the inclusion of the second and third measurement limits is done by reducing the voltage drops equal, respectively, lOU B and. C B with resistors 14 and 13, respectively, for which the switch 16 of the measurement limits should be switched to pins 18, 21 and 17, 20. For switching on first limit he must

0 to be connected to pins 19 and 22. The voltage corresponding to these limits from the transfer switch brushes 16 limits fall on its half-rings, and from them at the clip 23 of the measuring circuit.

In this way, the application of the proposed meter allows you to temper the dependence of the readings on the ambient temperature, since the block 8 of the reference resistor is constructed from equal-nominal resistors. These resistors, as well as all resistors 4 - 7

0 are strictly identical, i.e. the same design, from the same manganin, due to the fact that the ratio of their resistances depends little on the change in the temperature of the medium and on aging. Kpo.vie addition, the clinker decreases instability

5 indications due to the fact that the block 8 of the reference resistor consists of a group of resistors, since in the group there is a decrease in c: iychias of individual resistors due to averaging, as well as possibly

Q to carry out the correction of the readings of the second and third measurement limits by changing the resistances of the resistors 13 and 14, in-, luchu with adjustable, because slight changes in resistance in that part of coupled branched

5 of the circuit in which resistors 13 and 14 are located, the total resistance of the block 8 of the reference resistor between the top of the branching 9 and 11 of the current is practically not reflected. A decrease in the dependence of the readings on the medium temperature, as well as a correction of the indications of the lower limits of the measurement, increases the overall labor productivity in the operation of the instrument, since the time intervals between the standard calibrations of the model

5 potentiometers. The range of applicability is expanded due to increased accuracy, and hence its capital productivity increases. At the same time, material costs are reduced for providing special physical conditions in laboratory rooms that must be observed for particularly accurate measurements.

Claims (1)

Invention Formula Exemplary DC potentiometer containing current stabilization unit ten with rheostats, adjusting resistor, measuring decade, made according to a ring-sized circuit with a reference resistor having taps, limit switch, measuring circuit clamps, decade switch unit, the terminals of which 15 two of which are made adjustable, are connected to the taps of the measuring-deck-outputs adjustable connection resistors, with a current stabilization unit and with a switch-over resistor installed with the corresponding inputs, characterized in that it is a limiter. In order to increase the measurement measuring capacitance, the input and output of the reference resistor are connected to the contacts of the limit switch, made in a bipolar circuit, the reference resistor is made in the form of three pairs of parallel connected branches, two of which consist of three consecutive Cs (X and the third branch consists of two series-connected resistors connected in series with three parallel-connected chains of resistors, two of which consist of three series-connected resistors moat, one third - of the four series-connected resistors. 0 5 two of which are made adjustable, the outputs of adjustable resistors are connected to the corresponding switch inputs to increase the measurement dimension, the input and output of the reference resistor are connected to the contacts of the limit switch, made in a bipolar circuit, the reference resistor is made in the form of three pairs of connected pairs, two of which consist of three consecutive Cs (X are di-nip uniformly resistors, and a third branch consists of two series-connected resistors connected in series with t A reel is connected in parallel by chains of resistors, two of which consist of three resistors connected in series, one third of four resistors connected in series.