how to know which pin is collector ,which is emitter and which is base in a 3 pin phototransistor?

seandogue6 years ago
There are voltmeters that have transistor checkers built in, which can be used to identify the leads.

The best way, though, is to visit the mfg site and look it up.
iceng6 years ago
What are your skills ?
Do you have an ohm feature on your meter ?
What is the device number ?