I am building a high speed trigger project and i'm trying to use parts that I have in my spares box, I need an I.R detecting diode and have a couple but they are mixed with other clear package diodes in the same compartment in my box, they all look the same so is there a way to distinguish the I.R ones from the colour diodes since they are all in a clear package?

Neil.

 

Ohmmeter set to read megΩ. Red lead to cathode. Shine a uV source at the diode and see the change in reverse leakage. Use the ones that have the best response to IR.

All will show some ability to detect visible light, but the IR ones will show much less sensitivity to visible illumination.