First: Appearance distinguishing method:
On the surface, the first PNP transistor SMD housing than NPN ( D882 ) type case is much higher, additional NPN transistor SMD housing also has a projecting tag, followed by a PNP-type patch transistor 2 and pin 3 is connected to the high potential electrode P, SMD transistor of the NPN type 2 and pin 3 is the N pole, then the low potential, i.e. the two opposite pins are usually case, as long as these different surfaces can simply make a distinction.
Second: Universal method Meter distinction:
the red pen meter connected one pin and the black patch transistor further has two pins are connected to it can be detected two resistance values, the resistance when the two values are less than a few one hundred Euro, the second step test, the test leads reversed, the test is repeated once, if the measured resistance value is large, it indicates that the patch is a PNP type transistor, if the above is not satisfied, it means it is an NPN type paste film transistor.