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Typical application: Positioning
sensing in automation technology;
proximity sensors operate reliably
and without wear.
High frequency electromagnetic
field: The inductive sensor detects
all metals.
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- Different connection options using cable, connector or terminals.
- Modular efector m units with increased sensing range.
- Special application sensors for almost all application areas.
- Cylindrical housings with a diameter of 4 to 34 mm & rectangular housings.
- Wide range of fixing accessories and sockets.
Introduction
In all automated processes sensors are absolutely necessary to provide the PLC with information. They supply the necessary signals on positions, limits or serve as pulse pick-ups for counting tasks or for monitoring rotational speed. Inductive and capacitive sensors are nowadays indispensable for industrial usage. As compared to mechanical switches they offer ideal conditions: non-contact operation free from any wear and tear, high switching frequencies and accuracy. In addition, they are insensitive to vibration, dust and moisture. Inductive sensors detect all metals without contact, capacitive sensors almost all solid and liquid media such as metal, glass, wood, plastic, water, oil, etc.
Operating principle of inductive sensors
Inductive sensors take advantage of the physical effect of the change in the quality factor in a resonant circuit caused by eddy current losses in conductive materials. This is how it works: A LC tuned circuit generates a high frequency electromagnetic field. This field is radiated from the active face of the sensor. If a conductive material enters this field, eddy currents will be formed in accordance with the law of inductance which draw energy from the oscillator. This reduces the oscillation amplitude. The change is converted into a switching signal. The operating principle permits detection of all metals irrespective of whether they are moving or not. The distance to the active face at which an electrically conductive material causes a change of signal in the sensor is called sensing range. The sensing range of an inductive sensor is defined by means of a target of mild steel (Fe 360). If the switch is damped by other metals, e.g. aluminium or copper, this is reduced. Using correction factors the user can calculate the attainable sensing ranges.
Modular sensors
A special series of inductive sensors are the application sensors “efectorm”. The feature shared by these proximity sensors is an increased sensing range. Due to a universal connection technology the sensors can be used as 3-wire or 2-wire units. The integrated setting LED display reduces mounting time and ensure utilization of the increased sensing range. All units have a permanent laser-etched type label. This allows clear identification of the units even after many years.
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