SU712777A1

SU712777A1 - Resistance measuring method

Info

Publication number: SU712777A1
Application number: SU762426730A
Authority: SU
Inventors: Ленина Константиновна Спорышева; Андрей Александрович Новиков
Original assignee: Куйбышевский политехнический институт им. В.В.Куйбышева
Priority date: 1976-12-07
Filing date: 1976-12-07
Publication date: 1980-01-30

Description

1one

Изобретение относитс к измерительной технике, а имеино к способам пзмерени сопротивлений, и может быть использовано при построепин омметров дл пзмерени как малых, так и больших сопротивлепий. The invention relates to a measurement technique, and to methods for measuring resistances, and can be used in constructing ohmmeters for measuring both small and large resistances.

Известен способ измерени сопротивлени посредством вольтметра и амперметра, при котором амперметром измер ют ток, протекающий через резистор, а вольтметром - падение напр жени на последовательно соедииенных резисторе и амперметре 1 .There is a known method for measuring resistance by means of a voltmeter and an ammeter in which the current flowing through a resistor is measured by an ammeter and a voltage drop on a series connected resistor and ammeter 1 with a voltmeter.

Этот снособ используетс дл измерени больших сонротивлений, когда измер емое сопротивление много больше сонротивленп амперметра.This method is used to measure high resistances when the measured resistance is much larger than the resistance meter.

Иедостатком данного способа вл етс методическа погрешность, обусловленна ненулевым значением сопротивлени амперметра .The disadvantage of this method is the methodological error due to the non-zero value of the resistance of the ammeter.

Наиболее близок к описываемому изобретению известный снособ измерени сопротивлени посредством вольтметра и амперметра , при котором вольтметром измер ют падение иапр жени иа резисторе, а амиерметром - ток, нротекаюший в цепи параллельно соединеш ых резистора и вольтметра 2. Он используетс дл измерени малых сопротивлений, когда нзмер емое сопротивленне много меньше сопротпвлеии вольтметра.Closest to the described invention is a known method of measuring resistance by means of a voltmeter and an ammeter, at which a voltage drop is measured by a voltmeter and a resistor, and a current meter is flowing through a parallel connected resistor and a voltmeter 2. It is used to measure low resistances when measured. The resistance is much less than the resistance of the voltmeter.

Недостаток этого способа заключаетс в наличии методической иогрешностн пзмерени , обусловленной конечной величиной сопротивлени вольтметра.The disadvantage of this method lies in the availability of methodological measures due to the finite resistance value of the voltmeter.

Цель пзобретепи - повышение точности измерени .The purpose of the acquisition is to improve measurement accuracy.

Иоставлениа цель достигаетс тем, что вольтметр переключают параллельно амперметру и измер ют ток, а о величине соиротивлепи резистора суд т по формулеThe goal is reached by the fact that the voltmeter is switched parallel to the ammeter and the current is measured, and the value of the co-resistor is judged by the formula

П КPK

х - Г Лx - GL

где - сопротивленне исследуемого резистора;where is the resistance of the investigated resistor;

UY- падеиие 1апр женп на резисторе;UY- padeiie 1ppr resistor;

/А - ток, протекаюш,ий через амперметр при параллельно подключенном к амнерметру вольтметре./ A is the current flowing through the ammeter with a voltmeter connected in parallel with the amner meter.

На чертеже иредставлеиа блок-схема устpoiicTBa дл осуш,ествлени способа пзмеренп сопротивлени .In the drawing there is a depiction of an instrumental TBa for drying, as described in the method of resistivity.

Устройство содержит переключатель 1, вольтметр 2, измер емый резистор 3, амперметр 4.The device contains a switch 1, a voltmeter 2, a measurable resistor 3, an ammeter 4.

Claims

When measuring the voltage drop across the resistor 3, the voltmeter 2 connects parallel to the latter and the amner meter 4 connects to it in series, switch 1 is in position I. The voltage drop Well on the resistor 3 is equal to where and is the voltage applied to the circuit; D + RX is the resistance of the measured resistor; RV is the resistance of the voltmeter; l - resistance ammeter. When measuring the current, a voltmeter 2 is connected in parallel with an ammeter 4, and a resistor 3 is connected in series with them, switch 1 is in position II. Then the current / A flowing through the ammeter 4 is equal to / l--, the Resistance of the resistor Rx is calculated by the formula: It is equal to the resistance of the resistor. In this case, the methodological error of measurement -yy, which is calculated by the formula R. is zero. Connecting a voltmeter in parallel with an ammeter when measuring current makes it possible to eliminate the methodological error, drying through known methods of measuring resistance, by means of a voltmeter and ammeter. This makes it possible to build simple ohmmeters suitable for measuring both small and large resistances. Claim Method A method for measuring resistance based on measuring the voltage drop across a test resistor by means of a voltmeter connected in parallel with it and measuring an ammeter of current flowing through a resistor, characterized in that, in order to improve measurement accuracy, the voltmeter is switched in parallel with an ammeter and the current is measured and the resistance value of the resistor is judged by the formula: R where RX is the resistance of the resistor under investigation; UY is the voltage drop across the resistor; / A - the current flowing through the ammeter with a voltmeter connected in parallel with the ammeter. Sources of information taken into account in the examination 1. Electric measurements. Ed. A.V. Framke. L., “Energie, 1973, p. 140-141, fig. 836.

2. Electrical measurements. Ed. A.V. Fremke, L., “Energie, 1973, p. 140-141, fig. 83, a.