The difficulties encountered in recalibrating the Coleman instrument, either after replacing the exciter lamp or if the wave length has shifted, are familiar to most users. These difficulties may be overcome by a few simple modifications.
Joseph J. Kolb, "Modification of the Coleman Model 14 Universal Spectrophotometer to Simplify Wavelength Calibration Adjustment," Appl. Spectrosc. 15, 183-184 (1961)