How to choose the stop range of the multimeter
Human reading error in multimeters is one of the causes of measurement accuracy. It is unavoidable, but can be minimised as much as possible. Therefore, special attention should be paid to the following points in use:
1 Before measurement, the multimeter should be placed horizontally and mechanically zeroed.
2When reading, keep your eyes perpendicular to the pointer.
3 When measuring resistance, every time you change the gear should be zeroed. Replace the new battery when you can not adjust zero
4 measurement of resistance or high voltage, can not pinch the metal part of the pen, so as to avoid the human body resistance shunt, increase the measurement error or electric shock
5 in the measurement of resistance in the RC circuit, to cut off the power supply in the circuit, and the capacitor to drain the stored electricity, and then measured. After excluding the human reading error, we analyse other errors.
1. Multimeter voltage, current range selection and measurement error
The accuracy level of multimeter is generally divided into 0.1, 0.5, 1.5, 2.5, 5 and other levels. DC voltage, current, AC voltage, current and other gears, accuracy level calibration is by its maximum permissible error △ X and the percentage of the full-scale value of the selected range. Expressed by the formula: A% = (△ X / full-scale value) 100%1
(1) the use of different accuracy of the multimeter to measure the same voltage error
(2) with a multimeter with different ranges to measure the same voltage error
(3) Error arising from measuring two different voltages with the same range of a multimeter
