A Low-Cost Spectrometer Design for Enhancing Atomic Spectra Analysis in the Modern Physics Laboratory

Spectroscopy has become an important tool of modern-day sciences due to its wide-reaching applications. This importance has made higher precision more desired with spectrometers; this high precision often comes with a high price as well. Within the modern physics laboratory, analyzing atomic spectra from emission tubes is one of the best ways to calibrate a spectrometer as the known spectral lines allow for correct scaling. I designed a budget friendly spectrometer and implemented a respective procedure to enhance the accuracy of the "Atomic Spectra" experiment for the modern physics laboratory (PHY 372) at EMU. In calibrating the new spectrometer, we noticed that the mercury emission tube had some anomalies that we plan to investigate. We used the new spectrometer to compare a new mercury emission tube to our current one in addition to analyzing the emission spectra of hydrogen, helium, neon, argon, and krypton. The spectrometer images were digitized using the free program ImageJ and analyzed using the RGB color channels as a filter. Overall, the current spectrometer has resolving power of around 0.50 nm/pixel with a 5-megapixel webcam. Possible improvements to image quality as well as data processing and characteristic fitting are considered as well.