How to measure potentiometer
For the potentiometer with a switch, in addition to the above method should be detected potentiometer nominal resistance and contact conditions, should also be detected whether the switch is normal. First turn the potentiometer shaft handle, check the switch is flexible, switch on and off, whether there is a clear "click Da" sound. With a multimeter R * 1 ohm, two probes are respectively in potentiometer switch two outer welding piece, rotary potentiometer shaft handle, the switch is turned on, the resistance multimeter on the value indicated by the infinite (OO) into 0. Turn off the switch, and the pointer to the multimeter should return from "0" to "infinity". The switch shall be switched on and off during the measurement, and the action of each switch shall be observed. If the switch is in the "open" position, the resistance value is not equal to 0, and the resistance value in the "off" position is not infinite, then the switch of the potentiometer is damaged.
The appropriate range with a multimeter resistance profile, measuring double potentiometer resistance value of the potentiometer two groups respectively (i.e. A and C between the resistance value and A 'and C' between the resistance) and whether the nominal values are the same and. And then wire respectively potentiometer A, C 'and A' and C potentiometer short circuit, then the multimeter is used to measure the center head B, B 'between the resistance value in the ideal case, no matter what position to the rotating shaft of the potentiometer, B, B between the two resistance values should be equal to A, C or A' and C 'between the two resistance values (i.e., the multimeter pointer should always be on A, C or A' and C 'resistance on the scale of real). If there is a deflection of the multimeter pointer, the synchronous performance of the potentiometer is not good.
When measuring, choose the appropriate range of multimeter resistance profile, the two probes are respectively connected with a potentiometer two fixed pin lug, to measuring potentiometer total resistance with the same nominal value. If the measured resistance is infinite or greater than the nominal resistance, the potentiometer is shown to be open or variable. Then the two coat are respectively connected with either end of the potentiometer center head with two fixed end, slowly turn the potentiometer handle to position rotation from one extreme to the other extreme position, normal potentiometer, multimeter resistance value from the nominal values of hands instructions (or 0) to change continuously 0 ohms (or nominal resistance). The rotation process, needle should change smoothly, without any beating phenomenon. If in the process of adjusting the resistance value, hand beating phenomenon, the existence of the fault of bad contact potentiometer. The method of detecting straight sliding potentiometer is the same as this.
