As with other semiconductor devices, the temperature is affected by the temperature, and when the temperature rises, its dark resistance will fall. Temperature changes have great impact on spectral characteristics. Spectroscopy Temperature Characteristic Curve of Vulcanized Lead Photographic Resistance. Its peak moves as the temperature rises in the direction of the wavelength. Therefore, it is sometimes taking cooling measures in order to improve sensitivity or in order to accept far infrared light.
Commonly used photosensitive resistors are cadmium sulfide-optimized resistors, which are made of semiconductor materials. The resistance of the photosensor is varied in a strong variation of the amphoteric light (visible light), and its resistance (dark implant) can reach 1 to 10 mΩ under dark conditions; (Light) is only a few hundred to thousands of ohms. The sensitivity (ie, spectral characteristics) of the photosensor (i.e., spectral characteristics) with the human eye (0.4 ~ 0.76) μm is very close, as long as the human eye can feel the light, it will cause its resistance to change. Therefore, when designing the optical control circuit, the light source is controlled with incandescent bulbs (small electric bars), and the design is greatly simplified.
The light-sensitive resistance is not linear with a strong variation of the strength of the incident light, and it is not possible to use it as a linear transformation of photoelectric. This is where the user should pay attention to. The beginners can purchase a photometry (MG45 type), an incandescent lamp at night points, and directly measuring the resistance of the photosensor using the multimeter. When measuring, the photosensitive resistance should be paired with the light of the incandescent lamp, and then gradually pull the distance from the lamp (from near to far), observe the resistance change of the multimeter indication, and visually verifies the specimen of the photoresist to deepen it. Sensibility understanding.