Photoelectric detection methods have the advantages of high precision, fast response, non-contact, etc., and many parameters can be measured. The structure of the sensor is simple and the form is flexible. Therefore, the photoelectric sensor is widely used in detection and control.
Photoelectric sensors are the key components for photoelectric conversion in various photodetection systems. They are devices that convert optical signals (visible and ultraviolet laser light) into electrical signals.
The photoelectric sensor is a sensor in which a photovoltaic device is used as a conversion element. It can be used to detect non-electrical physical quantities that directly cause changes in light quantity, such as light intensity, illuminance, radiation temperature measurement, gas composition analysis, etc. It can also be used to detect other non-electric quantities that can be converted into light quantity changes, such as part diameter, surface roughness, Strain, displacement, vibration, velocity, acceleration, and the shape of the object, the identification of the working state, etc. Photoelectric sensors are widely used in industrial automation devices and robots because of their non-contact, fast response and reliable performance. New optoelectronic devices continue to emerge, especially the birth of CCD image sensors, opening a new page for the further application of photoelectric sensors.
The optical measurement and control system made by the different working principle of the luminous flux on the photoelectric element is various, and the output quantity of the photoelectric element (optical measurement and control system) can be divided into two types, namely, the analog photoelectric sensor and the pulse (switching) photoelectric sensor. The analog photoelectric sensor converts the measured photocurrent into a continuously changing photocurrent, which has a single-value relationship with the measured. The analog photoelectric sensor can be divided into transmission (absorption) type and diffuse reflection according to the method of measuring (detecting the target object). Type, shading (beam blocking) three categories. The so-called transmissive type means that the object to be measured is placed in the optical path, the light energy emitted by the constant light source passes through the object to be tested, and the transmitted light is partially projected onto the photoelectric element; the so-called diffuse reflection refers to the light emitted by the constant light source. Projected onto the object to be measured, and then reflected from the surface of the object to be measured and projected onto the photoelectric element. The so-called opacity refers to the flux of light emitted by the light source through a part of the object to be measured, so that the light flux is projected onto the photoelectric element. Change, the degree of change is related to the position of the object being measured at the optical path.