The 77250B-MC from Newport Corporation is a Hand Operated Monochromator that operates from 0.2 to 23 μm using Newport’s interchangeable diffraction gratings. It has a focal length of 125 mm and an aperture ratio of F/3.7. This monochromator is based on an Ebert-Fastie design that can be operated by hand and has a wavelength accuracy of 1 nm with a step resolution of 0.1 nm. It consists of Newport’s 74001 micrometer driven slit assembly that has an adjustable slit width of 3 mm and slit height from 2 to 12 mm. The monochromator has an optical axis height that can be adjusted using Newport’s 77387 mounting kits to match the source/detector.