How to make multimeter range selection and avoid measurement errors
Human reading error is one of the causes of measurement accuracy. It is unavoidable, but can be minimised. Therefore, special attention should be paid to the following points in use: 1 Before measurement, the multimeter should be placed horizontally and mechanically adjusted to zero; 2 The eyes should be kept perpendicular to the pointer when reading; 3 When measuring resistance, every time you change the block, you should adjust the zero. Adjust the zero when to replace the new battery; 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 electrocution; 5 in the measurement of resistance in the RC circuit, to cut off the power supply in the circuit, and capacitors stored in the power drain, and then measured. After excluding the human reading error, we analyse other errors.
Multimeter accuracy level is generally divided into 0.1, 0.5, 1.5, 2.5, 5 and other levels. DC voltage, current, AC voltage, current and other blocks, accuracy (** degree) level of calibration by its large permissible error △ X and the selected range fullness value of the percentage of the expression. Expressed by the formula: A% = (△X / fullness value) × 100% ......1
(1) the use of different degrees of accuracy of the multimeter to measure the same voltage of the error generated
(2) The error generated by measuring the same voltage with different ranges of a multimeter
(3) with a multimeter of the same range to measure the error generated by the different two voltages
