spectrograph

thingiverse

The text appears to be a set of instructions for calibrating and using a low-cost spectrograph, likely designed by the author for educational purposes. The calibration process involves taking a picture of fluorescent light spectra, drawing a rectangle around the spectral lines in ImageJ, and then finding the wavelength corresponding to each horizontal pixel location. This is done by plotting intensity vs. horizontal pixel location and matching peak locations to known wavelengths. The text also explains how to use a calibrated spectrograph to determine the wavelength of unknown spectra. This involves taking a photograph of the unknown source, finding the plot profile in ImageJ, copying the data to a spreadsheet program (Excel), and then using the calibration curve to find the wavelength corresponding to each horizontal pixel location. The author mentions that students can also examine light from various sources without worrying about damaging the device, such as looking at the Fraunhofer lines in sunlight, reflection spectroscopy, absorption spectroscopy, and fluorescence. Overall, the text is a clear and detailed set of instructions for calibrating and using a low-cost spectrograph.