When you don’t have data sheet of any transistor in your hand, you face trouble in determining legs of transistors. Here I will tell you, How to determine legs of a transistor using a multimeter.
Check the type of transistor:
set the multimeter to resistor measure mode at range 2000 ohm .Put black probe on middle pin and red on any pin left and right. If it shows value its PNP. If not, Interchange the probes. Now if it shows values its NPN.
Determine Legs: Suppose the transistor is NPN. Test the resistance between middle and right leg. here We found 771 ohm.
Test the resistance between middle and left leg. here We found 764 ohm.
How to determine legs of a transistor using a multimeter ?
NOTE: we know that middle leg is base. Base to emitter resistance is always higher than base to collector resistance. So checking the resistance value we can easily determine the emitter and collector.
Now verify With the data sheet: