The model 78819 spectral calibration lamp mount holds a calibration lamp securely at the input slit of an Oriel monochromator or spectrograph. The close coupling provides excellent throughput with minimum light leakage. A source with at least two spectral lines in the wavelength range of interest is required for users to perform a calibration on their instrument. Calibration is also required when using the model 78855 LineSpec CCD detector and its accompanying software. The 78819 lamp mount may be purchased separately or as a set with everything required to perform calibrations. Each set includes a power supply, HgAr lamp and the 78819 lamp mount. Please refer to models 78822(230 VAC) and 78812 (115 VAC).