15 July 2018

Just a brief note on calibration. In addition to the calibration plate I designed (which has not been terribly useful) there is this note on calibration using a CFL (mercury vapor light) from the PublicLab.org site, who sell their own inexpensive (albeit much larger) spectrometer for hobbyists.

Calibration is the key to getting sensible results from any spectrometer, and the difficulty in obtaining known spectra for assessing the capabilities of these $25 Spectrometers  has made it difficult for me to judge how well I can trust the various spectra I have been able to generate with the devices to date. I was able to verify that the spectra using the broad-band IR led source and a standard reflective mirror looked a lot like the one in the IR led data sheet. I looked at maybe using sources available from spectrascope suppliers but these tend to be quite expensive. But I would really like an inexpensive calibration method using a source with well-defined/known peaks within the 410 - 940 nm range and this CFL method looks like it just might fill the bill.