Eddy current proximity sensors and capacitive proximity sensors are usually applied in general industrial production areas because the environmental requirements of these two proximity sensors are low.

If the tested object is a conductive object or can be fixed on a metal object, the eddy current proximity sensor is generally used for its high response frequency, good anti-environment disturbance performance, wide application range and low price.

If the tested objects are non-metallic (or metal), level height, powder height, plastic, tobacco, etc., capacitive proximity sensor should be selected. The response frequency of this sensor is low, but the stability is good. Environmental factors should be taken into account while installing.

If the tested object is made of magnetic material or buried with magnet steel to distinguish the object moving with it, the Hall proximity sensor should be selected, for it charges the lowest price.

Photoelectric proximity sensors or laser sensors can be used when the environmental conditions are better free of dust pollution. Photoelectric proximity sensors have almost no effect on the object to be measured when they are working. Therefore, they are widely used in fax machine with relatively high requirements as well as tobacco machinery.

In the anti-theft system, the automatic door usually uses pyroelectric proximity sensors, ultrasonic proximity sensors and microwave proximity sensors. Sometimes, in order to improve the reliability of identification, these proximity sensors are often used in combination.

No matter which kind of proximity sensor is selected, attention should be paid to the requirements of working voltage, load current, response frequency, testing distance and so on.