Calibration device for fluorescence photometers

Abstract

A calibration device is disclosed for use with fluorescence photometers of the type which direct an excitation radiation at a sample to be tested, and then read the fluorescent emission from the sample to identify bacterial growth in the sample. In the past the emission reading accuracy of fluorescence photometers has been tested by passive standards. The known standards have some shortcomings, in that they may have varying characteristics with time and temperature, and further because they are difficult to manufacture without experiencing some variation between the standards. The present invention addresses the problem by generating a particular fluorescent emission and directing that emission towards a photometer to be tested. Since the emission which is directed outwardly of the calibration device is predetermined and known, this directed radiation can be compared to that which is read by the fluorescence photometer. In this way, a positive evaluation of the reading accuracy of the photometer can be made. In further embodiments of this invention, a second circuit is included in the calibration device for reading the excitation radiation from the photometer. The excitation radiation, as read, can be compared to that which the photometer was expected to generate. The emission radiation characteristics can be generated dependent upon the excitation radiation, or can be a fixed amount.

Dependencies are inferred from the claim text.