Photo-Emissive Cells consist of Cathode-C and Anode-A in vacuum tube, when the light arrive at Cathode, there are Free-Electrons flow to Anode-A. It is so called Photo-Electric Current,
Light collected at Photo-Conductor make the resistance of Photo-Conductor change High intensity will make resistance decrease.
Note that
- Photo-Conductive Cell provide slow Dynamic Response
- Sensitivity will decrease if longer wavelength , such as IR
•Wide Spectral Range
•Fast Response Time
•High Sensitivity
•Excellent Linearity
•Low Noise
•Good Frequency Response