Can a Hall sensor be tested with just basic test gear?

Question

I have an item of electro-mechanical equipment with several Hall-sensors buried deeply inside.

The Hall sensors may be Alegro Micosystems 01L, I have physical access to the ends of the leads, but not to the sensors themselves (hence not being 100% sure what they are.)

Is it possible to determine if the sensors are working with a multi-meter only? I think the sensors may be faulty, but would prefer not to start disassembling anything until I can get a positive confirmation. The equipment can be rotated, and at some point (not sure where) some magnets should pass by the Hall sensors.

(Update - I also have a 0-25v DC power supply and a random selection of resistors/capacitors)

Answer 1

If you have ONLY the multi-meter, I don't think you can do anything (at least if you indeed have the sensors you linked to) : if you don't power them, you won't get any output signal.

If in addition you can supply them (ideally use the supply already in place in your system, as to avoid risks of inverting polarity or using wrong voltage), then you can tests them with a multi-meter (in voltage mode) :

1. check you have indeed some supply voltage, and write it down (lets call it Vcc)
2. measure the voltage between ground and output while rotating very slowly the equipment : if they work well, the voltage should change while rotating.

Depending how many magnets there are, and how they are disposed, you might get a nearly constant voltage of Vcc/2 for most of the turn, and a different (bigger or smaller depending on the polarity of the magnet) once the magnets passes by. Or your might get several signals per rotation (if there are several magnets), or even a continuously changing signal (with average probably Vcc/2) if there are many magnets with alternating polarities.