Alternating light photometer with gas discharge lamp - has photo-electric transducers as radiation receivers with output signals fed to processor with scan and hold circuits

摘要

An alternating light photometer uses a gas discharge lamp as the radiation source. A cyclically-operating beam modulator is provided to generate periodically following measuring and comparison radiations. Photo-electric transducers serve as radiation receivers. Their signals are delivered to a signal processor containing scanning and hold circuits. The processor is controlled by scanning pulses of the modulator. The switching on of the gas discharge lamp occurs for only a short time, essentially during the opening of the radiation path through the modulator. This increases the serviceable life of the lamp and hence that of the photometer and its consistency of results. A signal generated by the scanning arrangement (9) of the modulator (2) can be used to switch the lamp (1) on and off.