What is the difference between a proximity switch and a photoelectric switch?

- Oct 11, 2019-

Many customers think that photoelectric switches and proximity switches are one thing. This is wrong. There are big differences between photoelectric switches and proximity switches. Although they belong to sensors, their principles and applications are different. Let's talk about the difference between them.


In the process of selection, what occasions use photoelectric switches, and what occasions use proximity switches? When the detection switch is inconvenient to approach the detection object or when the object to be detected is easily damaged, when the space is limited, and the object to be measured is small, the photoelectric switch can be used, which does not distinguish between metal and non-metal. When the detection switch is easy to access the object to be measured and is not easily damaged, the detection of the metal object uses an inductive proximity switch, and the detection of the non-metallic object uses a capacitive proximity switch.


Of course, the photoelectric switch and the proximity switch still have the same place. For example, according to whether the receiving light source of the photoelectric switch receives the light source to determine whether the switch operates, it is divided into a bright-pass type and a dark-pass type, and according to the form of the output circuit, the photoelectric switch Both the proximity switch and the proximity switch can be classified into a PNP type and an NPN type.


Proximity switches are generally used for metal detection. Generally, the distance is short, and the photoelectric switch can be operated by any object that can block light (metal, plastic, water, etc.) as long as it has a partition.


Proximity switches and photoelectric switches, although all belong to the same sensor, there are still some differences in the use of the two. Proximity switches can be used for high speed counting, detecting the presence of metal bodies, speed measurement, level control, detecting part sizes, and acting as contactless buttons. The photoelectric switch converts the input current into a light signal on the transmitter, and the receiver detects the target object according to the strength or presence of the received light.


Photoelectric switch (also known as photoelectric sensor) is the abbreviation of photoelectric proximity switch. It uses the occlusion or reflection of the beam by the detected object, and the circuit is gated by the synchronous circuit to detect the presence or absence of the object. Objects are not limited to metal, and all objects that reflect light can be detected.


Proximity switches (also known as proximity sensors) are used in industrial automation control systems to enable detection, control, and new switching elements that are fully contactless with the output link. When the switch approaches an object, a control signal is issued. The proximity switch, also known as the non-contact travel switch, is not only a stroke control and limit protection, but also a non-contact type detection device, which is used for detecting part size and speed measurement, and can also be used for frequency conversion counters and variable frequency pulse generation. Automatic connection of liquid level control and machining programs.


The difference between the photoelectric switch and the proximity switch lies in the way in which the object is detected. The transmitting tube of the photoelectric switch emits modulated light, and the receiving tube detects whether the light is received to determine whether there is an object; and the proximity switch is detected by its head. The induction of the head to determine the existence of the object.


What is the difference between a proximity switch and a photoelectric switch?

1. The proximity switch can only sense the metal. It can't be sensed by people or plastics, and other materials, and the distance is only a few centimeters. The photoelectric switch can sense the material, but it responds to the sensing object. The size of the ability is related, that is, the white sensing object is far away, and the black is close.


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2. The difference between the photoelectric switch and the proximity switch lies in the way of detecting the object. The transmitting tube of the photoelectric switch emits modulated light, and the receiving tube detects whether the light is received to determine whether there is an object; and the proximity switch is by its head. The detection of the detection head to determine the presence of the object.

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3. When the detection switch is inconvenient to approach the detection object or when the object to be detected is easily damaged, when the space is limited, and the object to be measured is small, the photoelectric switch can be used, which does not distinguish between metal and non-metal. When the detection switch is easy to access the object to be measured and is not easily damaged, the detection of the metal object uses an inductive proximity switch, and the detection of the non-metallic object uses a capacitive proximity switch. In addition to the above differences, of course, the photoelectric switch and the proximity switch still have the same place. For example, according to whether the receiving light source of the photoelectric switch receives the light source to determine whether the switch operates, it is divided into a bright-pass type and a dark-pass type. According to the form of the output circuit, both the photoelectric switch and the proximity switch can be classified into a PNP type and an NPN type.


Photoelectric switches and proximity switches, which are all sensors, but there are some differences in use and use.


Proximity switches are mainly used for high-speed counting, metal detection, speed measurement, component size detection, and contactless buttons. Photoelectric switches are used in areas such as photoelectric safety protection.


The photoelectric switch mainly converts the input current into an optical signal on the transmitter, and the receiver detects the target object according to the strength and quantity of the received light.