Design and Implementation of Low Cost Optical Spectrometer

Optical spectrometer has one of the largest applications in various fields ranging from basic component analysis to treating cancers. Optical spectrometer works in visible electromagnetic spectrum to find the composition of solution using wavelength properties of light. In this paper, we propose a cost-effective way to build a spectrometer, which can be used to identify adulteration. This absorption type spectrometer is built using convex lenses and a transmission type grating. The idea behind this was to make a low-cost, portable spectrometer by using a Complementary Metal Oxide Semiconductor (CMOS) image sensor, which can be derived from a webcam, as a detector. The solution under test is placed in the cuvette and the image of the spectrum is captured by the webcam. These images are further processed and compared with the reference spectrum image to find the absorption lines. Wavelength is approximated by using hue value for known spectrum obtained by converting RGB image to HSV (Hue, Saturation, Value).