In general industrial production sites, the eddy-current proximity switch and the capacitive proximity switch are usually selected. Because these two kind of proximity switch to the environment requirement condition is low.
When the object is a conductive object or can be fixed on a piece of metal objects, the general use of proximity switch, because of its high response frequency, anti-jamming performance, wide range of applications, low prices.
If the object is Non-metallic (or metal), liquid level height, powdery material height, plastic, tobacco and so on. The capacitive proximity switch should be selected. This switch has low response frequency but good stability. The impact of environmental factors should be considered during installation.
If the subject matter is a magnetic material or is buried in the object under test for the purpose of distinguishing the object that it is moving with, the hall proximity switch should be selected and its price is the lowest.
In the environment conditions are better, no dust pollution occasions, photoelectric proximity switch can be used. The photoelectric proximity switch works almost without any influence on the object being measured. Therefore, it is widely used on the tobacco machine in the high demand fax machine.
In the anti-theft system, the automatic door usually uses pyroelectric proximity switch, ultrasonic proximity switch, microwave proximity switch. Sometimes in order to improve the reliability of recognition, these proximity switches are often used in combination.
Whichever kind of proximity switch you choose, you should pay attention to the operating voltage, load current, response frequency, detection distance and other indicators of the requirements