SU399790A1 - METHOD OF REMOVING THE DEPENDENCE OF RESISTANCE - Google Patents

Description

;one

; The invention may be used in instruments for measuring and sorting out non-linearity of resistors; measuring dielectric resistances of various voltages without recalculation; remove the dependences ((J) of dielectrics and Rx f (I) transition

 resistances.

Graduation of the indicator scale. The ras, which is used in known ways, is designed to pass through a measured resistance of a constant current or the existence of a constant voltage across the input divider, therefore with a change in voltage iodine ), the graduation of the electronic voltmeter scale also changes.

. To obtain actual measured resistance values, correction factors have to be introduced, the measurement process is extended, the results are obtained as discrete values, the automation of the measurement process is difficult and often impossible.

The purpose of the invention is to simplify the measurement process.

:. This goal is achieved by simultaneously measuring and recording the resistance value and the varying voltage (current). The actual values of the measured resistance at a voltage varying on it (current through it) with a single-counting electronic voltmeter counting without recalculation are achieved in that the sensitivity of the electronic voltmeter is inversely proportional to the voltage across the measured resistance (current through it). The voltage across the test resistance (current through it) can be either constant or alternating in sign.

Indeed, the magnitude of the measured resistance is defined as

D 0 - - obp / 1

x -. (and

t /,

about

where UQ is a constant voltage; - ob-model resistor; Circuit - a voltage exemplary resistor. this implies

; -, (2)

Jo6

Since it is common, the Cob resistor can be neglected in the calculations. Denote::

7 / EX / O

Vo6 - -. (O)

where i / o is the output voltage of the electron ": its voltmeter; K. is the gain factor of an electron voltmeter. Substitute (3) into (2) and get D - 0 g - G, - Consequently, to get the resistance value RX on a real scale as t / o changes, it is necessary that the numerator of expression (4) be a constant value; UuK is const, i.e., the gain (sensitivity) of the electronic voltmeter is inversely proportional to the change in voltage Uf ,. When measuring low resistances fj x ° v f / o-f / where Ux is the voltage across the measured resistance. Since t / o is usually 100, the voltage can be neglected while maintaining sufficient accuracy. Then

R. f / ,.

Denote

r t out

  to

(7) in (6), get

TJ D) - 1) L

: / OBO-K

It follows that with an increase in the voltage t / o, which sets the current through the measure.

A method for removing the dependence of resistance on voltage (current), characterized in that, in order to simplify the measurement process,

measure the resistance value under a certain mipimalpa voltage on it and change the sensitivity of the measuring device synchronously and inversely proportional to the voltage (current) applied to

intent resistance. A variable resistance Rx and a synchronous decrease in sensitivity (gain K factor) of an electronic voltmeter are obtained by measuring the measured resistance in real scale without recalculation. The dependences of (U) or () are removed as follows: at a certain minimum value of the voltage on the measured resistance (current through it) and at the maximum sensitivity of the electropower voltmeter, the value of the test resistance is measured. Then the voltage (current) smoothly increases, and the sensitivity of the electronic voltmeter synchronously decreases. An electronic voltmeter probe device will show the actual value of the measured resistance at any voltage (current) greater than the specified value. Turning on the output of the electronic voltmeter samopishush, iy device, get a graphical dependence of R f (U) or R f (f.