Capacitive Proximity Switches
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	Main Page / Proximity Switches / Capacitive Proximity Switches / Filling Level Sensor
	Capacitive sensors are primarily used when the object to be detected is non-metallic. The most common materials sensed are: plastic, glass, wood and paper. Another common application is as a liquid level control in a bin or hopper. Capacitive sensors are ideal for this type of application, since they can be adjusted to ignore the side of the enclosure. Technical Information Capacitive proximity switches contain 4 main components: plate, oscillator, detection circuit and solid state switch. The sensor operates in a similar fashion to a simple capacitor. When the power is turned on, the oscillator detects the amount of capacitance between the external target and the metal plate in the sensor. As the target approaches, the capacitance increases. When the capacitance reaches a certain point, the oscillator begins to operate (the opposite of inductive sensors, in which the oscillator stops operating when the target approaches). Once the oscillation reaches a preset point, the detection circuit senses this, and signals the switch to change state. Variety of Styles and Shapes Specialty Capacitive Sensor: Filling Sensor Capacitive switches are stocked in a variety of styles and shapes. Some of the most common configurations are: 18 mm diameter (M18 x 1 thread) 30 mm diameter (M30 x 1.5 thread) This sensor measures 345 mm x 58 mm x 38 mm and is used to detect the fill level over a height of 300 mm. This single unit is composed of 10 individually adjustable sensor elements arranged in series. As the fill height increases, the elements are switched, one by one. This gives an output of 0-10 VDC over the 300 mm length. The sensor is fully enclosed (IP67), and can detect the fill height through a glass or plastic barrier. Capacitive Filling Level Sensor An information sheet including Selection Guide and Specifications will be sent on request.