Summary:
Illuminance sensor is a common detection device and has certain applications in many industries. In many places we see light-operated switch this kind of equipment, such as street lamps, each automatic weather station and agricultural greenhouses, but there was a ball when we see the box, although know this is a light sensor, but for it or don’t know, today we are going to know about the light sensor.
Working principle:
Illuminance sensor using hot effect principle, the main is the use of the reaction of weak light has higher detection components, these original induction actually like camera sensitive matrix, internal winding plating type multijunction thermopile, its surface coated with high absorption rate of the black coating on the hot junction on the induction, while cold joints in the body, hot and cold junction temperature electric potential. In the linear range, the output signal is proportional to the solar radiation. The visible light of the filter irradiates to the entrance photodiode, which is converted into an electrical signal according to the size of the visible illuminance, and then the electrical signal will enter the processor system of the sensor, so as to output the binary signal required.
Of course, there are many kinds of illuminance sensors, and some of them even optimize the structure introduced above, especially in order to reduce the impact of temperature, the illuminance sensor also applies the temperature compensation circuit, which greatly improves the sensitivity and detection ability of the illuminance sensor.
Usage:
The light intensity sensor should be installed in the surrounding open, no obstacles above the sensor surface. Adjust the sensor level position, and then firmly fix it, it is best to firmly fix the sensor on the mounting rack, in order to reduce breakage or intermittent interruption phenomenon in windy days.
Wall-mounted illuminance sensor installation method: first drill holes in the wall, then put the expansion plug into the hole, screw the tapping screw into the expansion plug.
Louver box type illuminance sensor installation method: louver box type illuminance sensor is generally used in outdoor weather stations, can be directly installed on the beam of the weather station through supporting plate or bending plate.
Wide voltage power supply input, 10-30V can be. When connecting the 485 signal, note that the A/B line cannot be connected inversely, and the addresses of multiple devices on the bus cannot conflict.
Precautions for use of illumination sensor:
1. Be sure to check the packaging is not intact, and then to check the transmitter model and specifications are not the same as the purchase of the product; Be sure to contact the seller as soon as possible if you have any questions.
2. When using the light sensor, there must be no external pressure stamping light detection sensor, so as to avoid the damage of the measuring element under the pressure stamping to affect the use of the light sensor or lead to abnormal light sensor or damage to the light film leakage phenomenon. The use of light sensors in high temperature and high pressure environments must be avoided.
3. When using the illuminance sensor, users are forbidden to disassemble the sensor, not to touch the sensor diaphragm, so as not to cause damage to the illuminance sensor.
4. Before using the illuminance sensor, be sure to confirm the output voltage of the power supply is correct; The positive and negative wiring of the power supply and the positive and negative wiring of the product shall ensure that the measured range is within the corresponding range of the illuminance sensor. Read the product manual or consult the seller in detail.
5. When installing the illuminance sensor, be sure to ensure that the surface is clean and placed on the measured surface.
6. The shell of the luminance sensor is strictly prohibited to be scratched, knocked or banged by knives or other sharp metal wires and objects, resulting in damage to the transmitter.