How to reduce errors in detecting DC currents?

First, the characteristics of detecting DC current with an pointer multimeter.

When the DC current is detected by using the pointer multimeter, the voltage of the multimeter will reduce the equivalent voltage of the circuit because the two pens of the multimeter are in series in the circuit to be detected, so that the current of the circuit will be reduced. That is to reduce the detected current. It can be seen that the influence of multimeter voltage on the voltage of the loop is related to the magnitude of the loop voltage when the DC current is detected by the exponential multimeter, especially when the voltage of the loop is lower. From the point of view of series resistor, the circuit with high circuit resistor has little effect. That is to say, the error of detecting high voltage and high resistor circuit current by using the pointer multimeter is small and can be ignored, but the detection error must be taken into account when detecting the current of low voltage and low resistance circuit.

Second, the method of reducing the error in detecting DC current.

In order to reduce the detection error, a large current range block (I. E. low internal barrier) should be used to detect DC current in order to reduce the detection error when using an pointer multimeter to detect DC current. If necessary, DC current can be indirectly measured by measuring the voltage at both ends of the circuit resistor and then calculating.

This article is from Allicdata Electronics Limited. Reprinted need to indicate the source.