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2022

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What is the principle of the bridge method of resistance measurement? How to measure resistance by bridge method


What is the principle of the bridge method of resistance measurement? The bridge method of measuring resistance. Knowledge about resistance measurement, you can use the bridge method to measure the size of the resistance, its working principle is what kind of, know three of the four resistance to find the remaining one, the following analysis of the bridge method of measuring resistance of the specific method for your reference.

Bridge method of measuring resistance

1、Working principle

When the bridge is balanced (that is, the current in the sensitive ammeter G is zero), that is, R1/R2 = R3/R4, only need to know three of the four resistances, you can find out the remaining one.

2、Measurement method

In the actual measurement, in order to facilitate the adjustment of the balance of the bridge, one of the bridge arms using a varistor box or using the length of the sliding wire resistance wire can be read out as shown in the figure on the right, by adjusting the sensitive ammeter G sliding head D, so that the current in the ammeter is zero, the bridge to balance, you can measure the length of the AD section and DB section L1, L2 by the formula: Rx = (L1 /, find the value of the resistance to be measured Rx.

3、Main features

Using the bridge method to measure resistance, the results are more accurate, depending only on the known resistance, the accuracy of the sensitive ammeter, and the electric potential of the power supply has no relationship, in the requirement for accurate resistance measurement can be used when this method.