the detection of the resistor

Third,the detection of the resistor

Will be two pen ( regardless of the positive and negative ) are connected with the two ends of the resistor can be connected to measure the actual resistance value ( in order to improve the measurement accuracy,the range should be selected according to the nominal value of the measured resistance.The deviation between reading and nominal resistance is 5 %, 10 %,or 20 %, respectively.If not,and beyond the range of deviation, it shows that the value of the resistance has changed.

Note : do not touch the conductive part of the stylus and the resistance when testing the resistance, especially when measuring the resistance above a few tens of kilo-ohm.when measuring the resistance on a circuit board,at least one head is to be welded, so as to avoid the influence of other components in the circuit on the test,resulting in measurement error. 

Fourth,the detection of potentiometer 

1 " 2 " on both ends of the ohm meter reading should be the nominal resistance of the potentiometer,if there is a lot of difference,the potentiometer is damaged.

Detect the contact between the active arm of the potentiometer and the resistance piece is good. Using the ohm stop of the multimeter to measure"1"2"(or " 2 " 3 "),turn the rotating shaft of the potentiometer to the position close to"off"according to anticlockwise direction,the smaller the resistance,the better.When the shaft handle is rotated slowly clockwise,the resistance value should be gradually increased,and when the shaft handle is screwed to the extreme position"3",the resistance value should be close to the nominal value of the potentiometer.