Unformatted text preview: KG • FP 1110 3. Magnetic proximity sensors 3.1
Reed proximity sensors 3.1.1 Function description
Magnetic proximity sensors react to the magnetic fields of permanent magnets and
In the case of a reed sensor, contact blades made of ferromagnetic material (Fe-Ni
alloy, Fe = iron, Ni = nickel) are sealed in a small glass tube.
The tube is filled with an inert gas i.e. nitrogen (inert gas meaning a non active, non
combustible gas). S Fig. 3.1.1: Magnetic reed proximity sensors If a magnetic field approaches the reed proximity sensor, the blades are drawn
together by magnetism, and an electrical contact is made. © Festo Didactic GmbH & Co. KG • FP 1110 35 3. Magnetic proximity sensors 3.1.2 Technical characteristics
The table below lists some of the most important technical data relating to
contacting proximity sensors. Parameter Value Switching voltage 12 – 27 V DC or AC Switching accuracy ±0.1 mm Maximum contact rating 40 W Maximum magnetic interference induction 0.16 mT Maximum switching current 2A Maximum switching frequency 500 Hz Switching time ≤2 ms Conduc...
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- Spring '12
- pH, proximity sensors, Festo Didactic GmbH, Festo Didactic GmbH & Co