Analysis of selection tips for proximity switches

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Switches are fairly common devices; in daily life, we can find them on the switches of sockets, on the doors of hotels and guesthouses, as well as on hair dryers and electric kettles. The switches chosen for different applications vary, as do the corresponding standards; therefore, the following analysis is provided on how to select proximity switches. In general industrial production facilities, eddy current proximity switches and capacitive proximity switches are usually chosen. Because these two proximity switches have lower requirements regarding the environment. When the object to be measured is a conductive object or one that can be fixed to a metal surface, an eddy current proximity switch is generally chosen, as it features a high response frequency, good resistance to environmental interference, a wide range of applications, and a low cost. If the object being measured is a non-metal (or metal), liquid level, powder level, plastic, tobacco, etc. In that case, a capacitive proximity switch should be used. This type of switch has a low response frequency but good stability. The impact of environmental factors should be taken into account during installation. If the object being measured is a magnetic material, or if magnets are embedded within it in order to distinguish it from other objects moving together with it, a Hall proximity switch should be used, as it is the least expensive option. In environments with good conditions and no dust pollution, photoelectric proximity switches can be used. When in operation, the photoelectric proximity switch has almost no impact on the object being measured. Therefore, it is widely used in high-performance fax machines as well as in tobacco machinery. In security systems, automatic doors typically use pyroelectric proximity switches, ultrasonic proximity switches, and microwave proximity switches. Sometimes, to improve the reliability of recognition, the aforementioned types of proximity switches are used in combination. Regardless of which proximity switch is chosen, attention should be paid to the requirements for parameters such as operating voltage, load current, response frequency, and detection distance.