Method and apparatus for measurement of the fluorescence relaxation period of a fluorescent substance

摘要

The subject of the present invention consists of a method and an apparatus for measurement of the fluorescence relaxation period of the radiation of a fluorescent substance whose fluorescence relaxation period is a function of at least one physical parameter. The fluorescence radiation is fed back to the output radiation in a regulating circuit, whose regulating parameter is a parameter for the physical parameter. This is accomplished by advancing the fluorescence radiation to a photoelectric receiver whose output signals are supplied to a voltage controlled oscillator following phase-sensitive rectification and integration. The fluorescence radiation is alternately phase-sensitively rectified only during the relaxation phase. The total durations of the different rectification periods in the two directions are identical. The alternatingly rectified signals are integrated.