How does the photoelectric cell of a photoelectric sensor work? What are its main characteristics?

Photoelectric cellIt is made based on the principle of external photoelectric effect. When light is irradiated onto a metal or metal oxide optoelectronic material, the energy of the photons is transferred to the electrons on the surface of the optoelectronic material. If the incident light energy on the surface gives the electrons enough energy,ElectronicsIt will overcome the attraction of positive ions and leave the material surface to enter the external space. Main characteristics: volt ampere characteristics, illumination characteristics, spectral characteristics, response time, peak detection rate, and temperature characteristics.

photoelectricityDoubling tube: Apply voltage to each doubling electrode during use. The cathode potential is the lowest, starting from the cathode, the points of each doubling electrode increase in sequence, and the anode point is the lowest. Due to the potential difference between adjacent doubling electrodes, there exists an accelerating electric field that accelerates electrons. The photoelectrons emitted from the cathode, accelerated by the electric field, hit the first multiplying electrode, causing secondary electron emission. eachElectronics58彩票The secondary electrons can be ejected from this multiplying electrode and accelerated by an electric field to hit the second multiplying electrode. By continuously multiplying, the number of electrons received by the anode will be 105 to 108 times that of the cathode. Main parameters: multiplication coefficient, photocathode sensitivity, total sensitivity of photomultiplier tube, dark current, spectral characteristics of photomultiplier tube.