How to use a multimeter to measure the size of inductance and resistance?
The pointer multimeter is composed of a meter parallel head, measuring circuit components and a changeover switch. It has two shapes, portable and pocket. The dial, zero adjustment knob, test jack, etc. are installed on the panel. The functions of various multimeters are slightly different, but there are four basic functions: one is to test DC current, the other is to test DC voltage, and the third is to test AC voltage, the fourth is to test the AC and DC resistance. Some multimeters can measure audio level, AC current, capacitance, inductance and special values of transistors, etc. Due to the difference in these functions, the appearance and layout of the multimeter are also different!
1. When measuring resistance with a multimeter, you should first short-circuit the test leads, turn the zero-adjustment potentiometer to zero, and make the pointer on the ohm zero position. If the pointer still does not reach 0, this phenomenon is usually due to the battery in the meter. If it is caused by insufficient voltage, it should be replaced with a new battery to measure accurately. Moreover, after each shift, the zero adjustment potentiometer needs to be readjusted for zero adjustment. When selecting the ohm gear, try to choose the resistance value to be measured at a position close to the resistance value reading in the center of the dial to improve the accuracy of the test results; if the resistance is on the circuit board, one of the legs should be soldered before testing. Otherwise, there are other shunt devices by the resistor, and the reading will be inaccurate! When measuring the resistance value, do not touch the test lead and the resistance pin with the fingers of both hands separately, so as to hinder the shunting of the resistance of the human body and increase the error.
2. Measure the inductance: put the multimeter in the R×1 block, connect the red and black test leads to any leading end of the inductor, and the pointer should swing to the right at this time. According to the measured resistance value, it can be identified in the following three situations:
A? The resistance value of the measured inductor is zero, and there is a short-circuit fault inside it. B? The DC resistance value of the measured inductor is directly related to the diameter of the enameled wire used to wind the inductor coil and the number of winding turns. As long as the resistance value can be measured, the measured inductor can be considered normal.
