Sensors are essential components in industrial automation. Below, the Transmission Network editor will explain in detail the differences between optical sensors and photoelectric sensors:
Optical sensors are devices that can sensitively detect light energy from ultraviolet to infrared light and convert it into electrical signals. Optical sensors are sensing devices mainly composed of photosensitive elements, and are primarily classified into four categories: ambient light sensors, infrared light sensors, sunlight sensors, and ultraviolet light sensors. They are mainly used in automotive electronics and intelligent lighting systems. Modern electrical measurement technology is becoming increasingly mature, and due to its advantages such as high accuracy and ease of connection to microcomputers for automatic real-time processing, it has been widely used in the measurement of electrical and non-electrical quantities. However, electrical measurement methods are susceptible to interference, and in AC measurements, the frequency response is not wide enough, and there are certain requirements for withstand voltage and insulation. With the rapid development of laser technology, these problems can now be solved.
A photoelectric sensor is a device that converts light signals into electrical signals. Its working principle is based on the photoelectric effect. The photoelectric effect refers to the phenomenon where, when light shines on certain materials, the electrons in the material absorb the energy of the photons, resulting in a corresponding electrical effect. Based on different phenomena, the photoelectric effect is divided into three categories: external photoelectric effect, internal photoelectric effect, and photovoltaic effect. Photoelectric devices include phototubes, photomultiplier tubes, photoresistors, photodiodes, phototransistors, and photovoltaic cells. The performance and characteristic curves of photoelectric devices are analyzed.
Photoelectric sensors generally consist of two parts: a processing path and a processing element . Their basic principle is based on the photoelectric effect, which converts the change of the measured quantity into a change of light signal, and then uses photoelectric elements to further convert the non-electrical signal into an electrical signal. The photoelectric effect refers to the phenomenon that when light shines on an object, it can be regarded as a series of photons with a certain energy bombarding the object. At this time, the energy of the photons is transferred to the electrons, and the entire energy of a photon is absorbed by an electron at once. After receiving the energy transferred by the photons, the state of the electron changes, thereby causing the object to produce a corresponding electrical effect. The photoelectric effect is usually divided into three categories: ( 1 ) The phenomenon that electrons can overflow from the surface of an object under the action of light is called the external photoelectric effect, such as phototubes and photomultiplier tubes; ( 2 ) The phenomenon that the resistivity of an object can change under the action of light is called the internal photoelectric effect, such as photoresistors and phototransistors; ( 3 ) The phenomenon that an object generates an electromotive force in a certain direction under the action of light is called the photovoltaic effect, such as photovoltaic cells.
Difference between optical sensors and photoelectric sensors
Sensors are familiar to everyone, and there is a large market demand for them. There are many types, among which optical sensors and photoelectric sensors are commonly used. Although they differ by only one word, the two are very different.
1. Different definitions:
A light sensor is generally a device that can sensitively detect light energy from ultraviolet to infrared light and convert that light energy into an electrical signal.
A photoelectric sensor is a sensor that uses photoelectric elements as its detection element. It first converts the change in the measured quantity into a change in light signal, and then uses photoelectric elements to further convert the light signal into an electrical signal.
2. Different working principles:
Optical sensor: Composed of a projector and a receiver. The projector focuses light through a lens, and then performs further switching and control. The light source of the projector varies depending on the needs, including general light bulbs, red light, green light LEDs , etc. The receiver receives the light signal sent by the projector and converts it into an electrical signal. Its main component is a silicon crystal component, which can be divided into phototransistors, photodiodes, and photoresistors. Nowadays, phototransistors are widely used in optoelectronic products because of their advantages of high-speed switching function and excellent sensitivity.
Photoelectric sensors: The transmitter aims at the target and emits a light beam, which typically originates from a semiconductor light source, such as a light-emitting diode ( LED ), laser diode, or infrared emitting diode. The light beam is emitted continuously or with varying pulse widths.
