A system and method for self-checking a fluorometer for failure or deteriorated performance includes fluorescent reference standards mounted on a support to move with respect to one or more fixed fluorometers. The intensity of the fluorescent emission of the fluorescent reference standard is initially measured with the fluorometer, and, after a prescribed interval of usage of the fluorometer, a test measurement of the intensity of the fluorescent emission of the fluorescent standard is taken with the fluorometer. The test measurement is compared to the initial measurement, and failure or deteriorated performance of the fluorometer is determined based on a deviation of the test measurement from the initial measurement.