Pulsed radiation detector system
AssigneeThe Perkin-Elmer Corporation
InventorMichael Alan Ford
Life of this patent
Estimating the term…
Abstract
Disclosed is a fluorescence spectrometer having an intermittently activated sample irradiating source, such as a UV lamp, the periods of activation being short (e.g., 100 microseconds) in comparison to the intervening inactive periods (e.g., 20 milliseconds). Fluorescence radiation emitted by the sample is detected by a photomultiplier, the output signal of which is supplied to an integrating amplifier for utilization. A field effect transistor (FET) in the output circuit of the photomultiplier has its gate coupled to a control unit which determines the activation periods of the lamp and, in timed relation thereto, cuts off the FET to interrupt the output circuit during periods that the lamp is inactive. A dual channel fluorescence spectrometer is also described.
Claims10
A pulsed radiation detector system comprising, in combination:
- a. a source of electromagnetic radiation;
- b. an electromagnetic radiation detector;
- c. means, including control means, intermittently energizing said radiation source to cause emission of radiation flashes having a duration which is short in comparison to intervals between flashes;
- and
- d. switching means operative in timed relation with said control means for making available the detector output or an electrical quantity derived therefrom in a signal utilization channel during successive activation periods, each of which periods includes a flash duration and is also short compared with said intervals.
A pulsed radiation detector system comprising, in combination:
- a. a source of radiation for irradiating a sample to fluorescence;
- b. means, including control means, for intermittently energizing said radiation source to cause fluorescent emissions by said sample of radiation flashes having a duration which is short in comparison to the intervals between flashes;
- c. radiation detection means positioned to receive radiation from said sample and generate an output signal in response thereto;
- d. means coupling the output signal of said detection means to a signal utilization channel;
- and
- e. switching means associated with said coupling means and operative in timed relation with said control means to interrupt the coupling of said output signal to the utilization channel during periods substantially coinciding with the intervals between flashes.
A dual-channel fluorescence spectrophotometer, comprising:
- a. a source of radiation for irradiating a sample;
- b. means, including control means, for intermittently energizing said radiation source to cause fluorescent emission by said sample of radiation flashes having a duration which is short in comparison to the interval between flashes;
- c. sample photodetector means positioned to receive radiation from said sample and generate a sample output signal in response thereto;
- d. reference photodetector means positioned to receive an attenuated radiation flux from said source and generate a reference output signal in response thereto;
- e. respective sample and reference integrating amplifiers coupled to receive the output signals of said sample and reference photodetector means;
- f. respective switching means coupled between the output of said photodetectors and input of said integrating amplifiers and operative in timed relation to and by said control means for substantially simultaneously interrupting the coupling between said photodetectors and amplifiers during periods substantially coinciding with said intervals between flashes;
- and
- g. means for ratioing the output of said amplifier to generate a signal substantially free from the effect of fluctuations in the radiation output of said source.
Dependencies are inferred from the claim text.