Measuring principle of the illuminance meter
The photovoltaic cell is a photoelectric element that directly converts light energy into electrical energy. When light is directed to the surface of the selenium photovoltaic cell, the incident light passes through the metal film 4 to reach the demarcation surface of the semiconductor selenium layer 2 and the metal film 4, and produces a photovoltaic effect at the interface. The size of the generated photogenerated current has a certain proportionality to the illumination on the light-receiving surface of the photocell. At this point, if an external circuit is connected, a current passes through, and the value of the current is indicated from a microampere meter graduated in lux (Lx). The magnitude of the photocurrent depends on the intensity of the incident light. The illuminance meter has a variable-speed device, so that it can measure high illuminance as well as low illuminance. Cite the type of illuminance meter:
1. Visual illuminance meter: inconvenient to use, not high precision, rarely used
2. photoelectric illuminance meter: commonly used selenium photocell illuminance meter and silicon photocell illuminance meter
The difference between UV illuminance meter and illuminance meter
UV illuminance meter and illuminance meter are instruments for measuring light intensity, but UV illuminance meter measures the intensity of ultraviolet light, while the illuminance meter is to measure the intensity of visible light. Looks like the name is almost the same, but the function is very different.
UV illuminance meter is also called ultraviolet irradiance meter, the unit is mainly mW/cm2 or uW/cm2. according to the ultraviolet band, can be divided into UVA, UVB, UVC, etc., the different bands of ultraviolet light used in different occasions. For example, UVC band of ultraviolet light is mainly used for sterilization, UVB band of ultraviolet light is used for skin disease treatment, UVA band of ultraviolet light is used for curing. So in the choice of UV illuminance meter should also be based on the light source of the band to choose.
Illuminance meter is used to measure the luminance, brightness of the instrumentation, the unit is Lux, mainly used in public places light illumination detection, lighting production industry, photography industry, stage lighting arrangements and other places.
