Digital detector for photometric measuring of small brightness differences, has photosensor operated at constant voltage and compensation current is generated, compensation and sensor currents are subtracted and result is integrated

摘要

Photosensor is operated at a constant voltage and a compensation current is generated. The compensation and sensor currents are subtracted and the resulting current is integrated, thus attaining a photometric measuring rendition, higher by several decades. Photodiodes, phototransistors, photoresistors, photomultipliers, or photocells may be used, typically a digital, light-proportional output signal is generated and simultaneously controls the internal flow.