Symbiolab added a new device to our DIY labware repository. Based on the designs from PublicLab and the hackaday prize entry by Brian Benchoff, we built a simple UV-Vis spectrometer for the analysis of liquid samples.
The construction uses two razor blades which are adjusted and screwed in place very close together to form the slit and the underside of a DVD is used as the diffraction grating, placed on a web-cam to capture the image. Two light sources are used, a white LED for transmission spectra and a UV LED placed perpendicular to the slit for fluorescence measurements. Both are powered with a 9V battery and connected to a switch. the internal construction holds a space for standard sized cuvettes. To minimize any unwanted light effects, the housing was laser-cut from wood and all potential holes except slit were covered with black paper and thin/transparent layers of the construction and housing were painted with a black marker.
The device is used together with Spectral Workbench, the open source online spectral analysis tool provided by PublicLab, but should also work with Spekwin32, another fantastic open-source software for spectral analysis, which packs a bunch of functionality!