Use of an A-C Polarized Photoelectric Cell for Light-Valve Bias Current Determination
The use of an a-c polarizing potential on a gas type PEC produces an alternating output current as compared with the continuous current obtained with a d-c polarizing potential. If the output voltage from the cell is suitably connected to a conventional audio-frequency amplifier and copper-oxide rectifier meter, the equipment may be conveniently used as an exposure meter. When used for the line-up of variable-density light-valves, the proper bias current, lamp adjustment, and lamp current may be readily determined. Variations of valve spacing and lamp current are also indicated. Numerous other applications for such a meter are being considered.
- Print ISSN
- 0097-5834
- Published
- 1939-10
- Content type
- Original Research
- DOI
- 10.5594/J11939
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