When the multimeter hits the diode gear (beep gear) to measure the triode... First we need to determine which foot is the b pole. So touch any one of the feet with the red test pen and do not move. Use the black test pen to touch the other two feet. If you can measure two sets of numbers that are close and less than 1. It means that the red pen is in contact with the b pole at this time. If the two groups of numbers measured are not similar...it means that the red pen is not touching the b-pole at this time...the red pen should be replaced with one foot...the black pen should measure the other two feet...until the b-pole is found... Suppose we know which foot is the b-pole...how to judge the c-pole and e-pole of the other two feet!
The black pen does not have two sets of similar data on the other two feet... One of the sets of data will be slightly larger... This foot is the e-pole. The small foot is c-pole.... And we know that this tube is an NPN type triode. Because the red pen is at the b pole! And the measurement method for the PNP type triode is the same... It's just that the black test pen is at the b pole... The red pen touches the other two feet and can measure two sets of similar data.
