A high intensity monochromator has been designed which provides maximum versatility and flexibility in providing high intensity output of ultraviolet and visible light of an intensity effective and useful in biological studies. The monochromator incorporates automatic calibration and direct recording of exposure intensity and duration. The instrument uses standard commercially available parts designed for stability and reliability so that maintenance can be reduced to a minimum, and operating procedure is quite simple. The output of the high intensity monochromator between 200 and 600 mμ using all three units is approximately twice the solar radiation at the earth's surface assuming no atmospheric attenuation. The time required to give a minimal erythemal dose to the untanned human skin of the abdomen is usually from 15 to 25 seconds but times as low as four to six seconds have been observed at 300 mμ using 50 Angstrom (A) bandwidth.
Knox JM, Warshawsky J, Lichodziejewski W, Freeman RG. Design of a High Intensity Monochromator. Arch Dermatol. 1967;95(3):319-322. doi:10.1001/archderm.1967.01600330077016