Patent ID: 8094302
Filing Date: 2012-01-10
Classification: G01J,G01N

Abstract:
1. A spectrophotometer comprising: a light source; a sample cell; an excitation optical system for extracting an excitation light component from light emitted from the light source and delivering the excitation light component to the sample cell; a fluorescence optical system for extracting a fluorescence component from light emitted from the sample cell; a photodetection unit having a photomultiplier tube for detecting a fluorescence component extracted by the fluorescence optical system, the photodetection unit outputting a signal corresponding to an amount of light detected by the photomultiplier tube at a constant frequency; a signal prediction part for predicting a strength of an output signal from the photodetection unit during subsequent periods per period sequentially based on the output signal from the photodetection part; and a control unit for adjusting a voltage applied to the photomultiplier tube based on a predicted value predicted by the signal prediction part so that a strength of an output signal from the photodetection unit during subsequent periods does not exceed a reference value of a strength of an output signal from the photodetection unit which defines a limit of electrical current passing through the photomultiplier tube.