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  • satchelfrost commented on satchelfrost's instructable Student Spectrophotometer7 months ago
    Student Spectrophotometer

    For this specific instrument: only methods using the visible spectrum will work. That means if you are trying to build a similar instrument to say detect ammonia then you should search for a methodology for doing this in the visible spectrum. Now if you are only ever going to use the instrument for one (or a few) types of molecules then you might simplify the design by finding wavelengths where these molecules have a high peak in the visible spectrum and use specific LEDs that only have most of their intensity around those wavelengths (also they make LEDs in many wavelengths, so you are not restricted to visible). If you use this latter method then you can omit the diffraction grating (CD), light bulb, and motor. I'm not sure if ammonia or oxygen exhibit wavelengths in the visible (def...see more »For this specific instrument: only methods using the visible spectrum will work. That means if you are trying to build a similar instrument to say detect ammonia then you should search for a methodology for doing this in the visible spectrum. Now if you are only ever going to use the instrument for one (or a few) types of molecules then you might simplify the design by finding wavelengths where these molecules have a high peak in the visible spectrum and use specific LEDs that only have most of their intensity around those wavelengths (also they make LEDs in many wavelengths, so you are not restricted to visible). If you use this latter method then you can omit the diffraction grating (CD), light bulb, and motor. I'm not sure if ammonia or oxygen exhibit wavelengths in the visible (definitely check their IR and also what IR LEDs are available) but maybe you can find a paper where these molecules complex with a chemical to make a wavelength which can be detected by the instrument. Or who knows maybe you will find a better method. If you're trying to do quantitative analysis you need to take into consideration the limit of detection of your instrument (depending on how accurate you actually want to be). Finally, with pH you're better off buying a pH meter or making your own using arduino. If your knowledge of chemistry isn't very good I'd be happy to clear up anything I can, but your question is very broad so I can't really give you a yes or no.

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  • satchelfrost followed GreatScottLab7 months ago
  • satchelfrost posted an instructable Wahfoekeep7 months ago