|MadSci Network: Physics|
Hi James: I learned some interesting things about UV detectors in this search. There are a couple of companies out there with outstanding detectors. 'Hamamatsu Photonics' is usually the first company I go to for photo-detectors. There is another company called 'United Automation' with a series of detectors under the 'Sunx' label. But the detector I chose for you was from 'Laser Components'. You can check out their site at the following address: http://www.lasercomponentsusa.com/ifw_jep_5-400.htm I would use their diode in a circuit similar to the following: You will need to order such a diode from the company, or one of their manufacturer's rep's - you will not find it in a typical electronics store. Use between 5 to 9Vdc for VCC, set the device in an enclosure, and have only a port-hole opening for the detector. Keep in mind that if you cover the port-hole with anything, it may prevent the UV, and may end up desensitizing your detector. Lastly, set both potentiometers to their lowest settings, then while exposed to a known source of UV, slowly adjust the potentiometers until you get a proper trip threshold and gain combination. If I may suggest, do the following: First nudge up the gain potentiometer just a bit only. Then move the threshold potentiometer through it's entire cycle. If nothing happens, then nudge the gain up a littel higher, and cycle the threashold potentiometer again, and continue until you find the proper trip point. With this circuit, the sensitivity can easily be adjusted by adjusting the gain potentiometer. Good luck!
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