Alignment and pathlength in a cell may be verified by projecting a laser beam into the cell. If a spectrometer has laser light in its optical path, that will sometimes suffice. If the spectrometer does not have laser light, then an auxiliary laser must be used. This can be a laboratory laser, or a pointer laser. With most of the cells, Infrared Analysis, Inc. supplies a mounted pointer laser with an on-off switch. This laser device can easily be placed in or out of the infrared beam. The laser device can be purchased as a separate item.