The model 17 uses the Cary 17 prism + grating monochromator. Only this model of the three DSM models provides the option of computerized slit width adjustment during scanning (as opposed to automatic high voltage adjustment and fixed slit width). This monochromator has a NIR potential to 2600 nm and this potential can be used in absorbance measurements when the PbS detector is used in place of the photomultiplier tubes. When enhanced for fluorescence applications, the model 17 is usable as a scanning excitation, fixed wavelenth emission syste. This model is capable of angstrom resolution throughout most of its range.