A diod is a diod, not a resistor.
See it as a current source, and put it into a opamp to form a current to
voltage converter...

Robert Wolcott wrote:
I have a silicon photodiode and I'm unsure if it is working or not. How
would I go about testing it? Things I have done so far:

Measured the resistance - 50 megs in either orientation, regardless of
lighting condition.
Measured resistance with a 5mw diode laser shining on it.

Anything else I should do? How do these typically fail?

Thanks,
Bob