A proximity switch is a kind of doesn't need motion artifacts in mechanical equipment and touch to the part of the actual operating power switch, when objects close to switching, magnetic induction surface to the spacing between the induction, without mechanical equipment touch, can make the power switch, and then drive ac or dc power supply device or computer equipment instructions. A proximity switch is a kind of power switch type sensor (namely non-contact switch), it has the characteristics of a proximity switch or toggle switch, but also has sensing technology characteristics, reliable action, stable characteristics, fast frequency response, long application life, anti-interference ability, etc. And with waterproof, corrosion resistance and other characteristics, products are eddy current type, inductance type, capacitance type, hall, photoelectric type, pyroelectric type, and other forms.

（IM08 inductive proximity switch）

It is widely used in CNC lathes, the metallurgical industry, chemical plants, the textile industry and packaging printing and other manufacturing industries. The automatic control system can be used as a limit, counting, positioning control and automatic protection link. The application of proximity switch is becoming more and more common, its own development trend and the rate of independent innovation is also very fast.

The main function of the proximity switch

1. Check the spacing
Inspect the termination, start and operation of the elevator and lifting platform; Test the car to avoid collision between two objects; Inspecting the parts of mechanical equipment in the work; Check the end part of the rotating body, the opening or closing of the gate valve; Inspect piston rod movement in a cylinder or hydraulic cylinder.

2. Size manipulation
Specification of metal sheet manipulation equipment; Automatic selection, identifying the length of metal products; Test the heap aspect ratio during automatic loading, unloading and handling; Examine the length, width, height and volume of the object.
Inspect the existence of items, check whether there are commodity packaging cases in the production and manufacturing packaging line; Inspect the availability of commodity parts.

3. Speed ratio and rate control
Control the speed of the conveyor belt; Control the rotational speed ratio of rotating mechanical equipment; Operate speed ratio and speed with various pulse counters.

4. Counting and manipulation
Check the number of goods that flow through the production line; High speed rotating shaft or disk speed measurement verification; Parts counting.

5. Abnormal inspection
Check whether the bottle cap is available; Distinguish goods up to standard and not passing; Check whether the metal in the gift box is defective; Distinguish metal material from non-metallic material parts; Commodity has no identification plate inspection; Lifting equipment danger zone alarm; Safety escalator start and stop.

6. Metrological verification and manipulation
Automatic metrological verification of goods or parts; Check the scope of the meter, and instrument panel and control the number of total flow; Test buoy control measurement surface height-width ratio, total flow; Check the iron buoy in the stainless steel soup bucket; Instrument panel measurement range limited or low limit control; Flow monitoring, plane manipulation.

7. Identify the target
Discriminate according to the code on the medium.

8. Transmission of information content
ASI(System bus) connects the sensors on each part of the machine and equipment to transmit data information back and forth in the production line, etc.