Multimeter application technique measure skills

1,the road test diode,transistor,voltage regulator tube is good or bad,because in the actual circuit,bias resistors or diode triode,voltage regulator tube peripheral resistance is compared commonly big,mostly over hundreds of thousands of ohm,in this way,we can use the multimeter R * 10 Ω or R electricalmotor1.blogspot.com 1 Ω shift to measure the p-n junction of the road. In road measurement,measurement in R x 10 Ω gears p-n junction should have a clear direction,features (if the positive and negative to the resistance differs not quite apparent,can convert R x 1 Ω file to test),generally positive resistance at R x 10 Ω file whose hands should be instructed in about 200 Ω,time measurement motor run capacitor in R x 1 Ω file whose hands should be indicated when measuring around 30 Ω (according to different phenotypes may differ ac electric motor slightly). 

Forward resistance is too big or reverse measurement results if the value is too small,suggests that the p-n junction has a problem,the tube also have a problem. This method was especially effective for maintenance,can very quickly find out bad tube,even has not been fully broken can be detected but bad tubes. For example,when you use small resistance profile measurement is a PN junction resistance is ac induction motor too large,if you put it down with the commonly used welding Ω R x 1 k file and test,may be normal,in fact,the characteristics of the tube has gone bad,cannot work normally or unstable.2,measuring resistance: it is important to choose the right range,when the pointer instructions from 1/3 to 2/3 full scale measurement precision is highest,the most accurate. Note that in R x 10 k ohms resistance measured level of resistance values,not to fingers on both ends of the resistance,so that the body resistance will make small measurement results.