The application field of the photoelectric switch sensor(1)

Photoelectric sensors using photoelectric elements as sensitive elements have a wide variety and wide applications. According to the output properties of photoelectric sensors, they can be divided into two categories: (1) photoelectric measuring instruments made by converting the measured into continuously changing photocurrent can be used to measure the intensity of light and physical quantities such as temperature, light transmission capacity, displacement and surface state of objects. For example: illuminance meter, photoelectric pyrometer, photoelectric colorimeter and turbidity meter for measuring light intensity, photoelectric alarm for preventing fire, automatic detection devices and instruments for checking the diameter, length, Ovality and surface roughness of processed parts, and their sensitive elements are photoelectric elements. Semiconductor optoelectronic components are not only widely used in civil industry, but also play an important role in military. For example, lead sulfide photoresist can be used to make infrared night vision instrument, infrared camera and infrared navigation system; (2) Convert the measured into a continuously changing photocurrent. Various photoelectric automatic devices are made by using the characteristics of "yes" or "no" electrical signal output of photoelectric elements when exposed to light or no light. The photoelectric element is used as a switching photoelectric conversion element. For example, photoelectric input device of electronic computer, switching temperature regulating device and digital photoelectric tachometer for speed measurement, etc.

1、 Soot turbidity monitor(photoelectric switch sensor)
Preventing industrial dust pollution is one of the important tasks of environmental protection. In order to eliminate industrial smoke pollution, we must first know the smoke emission, so we must monitor the smoke source, automatically display and over standard alarm. The turbidity of smoke and dust in the flue is detected by the change of light transmission in the flue. If the flue turbidity increases, the light emitted by the light source is absorbed and refracted by the soot particles, and the light reaching the photodetector decreases. Therefore, the strength of the output signal of the photodetector can reflect the change of flue turbidity.

2、 Bar code scanning pen(photoelectric switch sensor)

When the scanning pen head moves on the bar code, if it encounters a black line, the light of the LED will be absorbed by the black line, and the photosensitive triode cannot receive the reflected light, showing high impedance and in the cut-off state. When meeting the white interval, the light emitted by the LED is reflected to the base of the photosensitive triode, which generates photocurrent and turns on. After the entire bar code has been scanned, the photosensitive triode deforms the bar code into electrical pulse signals. The signals are amplified and shaped to form a pulse train, and then processed by the computer to complete the identification of bar code information.