Illuminance Meter - Illuminance Meter Measurement Principle
Photovoltaic cells are photoelectric elements that directly convert light energy into electrical energy. When the light hits the surface of the selenium photocell, the incident light passes through the metal thin film 4 and reaches the interface between the semiconductor selenium layer 2 and the metal thin film 4, and a photoelectric effect is generated on the interface. The magnitude of the generated photocurrent is proportional to the illuminance on the light-receiving surface of the photocell. At this time, if an external circuit is connected, a current will flow through, and the current value will be indicated on a microammeter with lux (Lx) as the scale. The magnitude of the photocurrent depends on the intensity of the incident light. The illuminance meter has a shifting device, so it can measure high illuminance and low illuminance. Types of illuminometers: 1. Visual illuminometer: inconvenient to use, low in accuracy, rarely used 2. Photoelectric illuminometer: commonly used selenium photocell illuminometer and silicon photocell illuminometer
