Error Analysis of Digital Multimeter(1)

Voltage and current range selection and measurement error of multimeter

The accuracy grades of multimeter are generally 0.1, 0.5, 1.5, 2.5, 5, etc. The calibration of accuracy level of DC voltage, current, AC voltage and current is expressed by the percentage of the maximum absolute allowable error x and the full value of the selected range.

The error caused by multimeter measuring voltage is different from that produced by measuring the same voltage by using multimeter with different accuracy. In selecting multimeter, the higher the accuracy is, the better. With a multimeter with high accuracy, it is necessary to select a suitable measuring range to give full play to the potential accuracy of the multimeter. The error of measuring the same voltage with different range of a multimeter is also different. In the case of satisfying the value of the measured signal, we should choose the file with a small range as far as possible, so that the accuracy of measurement can be improved. Therefore, when measuring the voltage, the measured voltage should be indicated above 2/3 of the multimeter range, so that the measurement error can be reduced.