What is the measurement principle of the illuminance meter?
An illuminance meter (or lux meter) is an instrument that specializes in measuring illuminance. It is to measure the degree of illumination of an object, that is, the ratio of the luminous flux received by the surface of the object to the area illuminated. The illuminance meter is usually composed of a selenium photocell or silicon photocell with a filter and a microammeter.
Measuring Principle
Photocell is a photoelectric element that converts light energy directly 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 dividing surface of the semiconductor selenium layer 2 and the metal film 4, and produces a photoelectric 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
Scope of application
General public places in order to ensure that people can live in a suitable light.
China has developed a health standard for indoor (including public places) illuminance, the use of illuminance meters for illuminance measurements in various places.
Lighting production industry, photography industry, stage lighting setup, etc.
The illuminance meter has been successfully applied to a number of programs, such as lighting production, photography, stage lighting arrangements, etc. Different models of illuminance meters can meet different measurement requirements.
Factory production line applications
In factories, production line lighting requirements are more stringent, continuous work will cause visual fatigue, so that the work efficiency greatly reduced, usually illuminance requirements ≥ 1000Lx, for the lighting requirements of higher places can choose a large range of illuminance meter, large range range, can cope with strong light illuminance measurement.
Illuminance meter has a wide range of applications, including our daily life in the application, such as factories, warehouses, schools, offices, homes, street light construction, laboratories and so on.
Illuminance Standards for Offices and Roads and Specific Environments
The JIS standard provides recommended illuminance values for various environments, and the following are the standard values it sets.
