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Unformatted text preview: f the object. The size, surface, shape, density and colour of the
object as well as the angle of impact determine the intensity of the diffused light so
that as a rule only small distances within a range of a few decimeters can be
scanned. The background must absorb or deflect the light emission, i.e. when an
object is not present, the reflected light beam must be clearly below the response
threshold of the receiving circuit. Fig. 6.4.1: The principle of diffuse sensors © Festo Didactic GmbH & Co. KG • FP 1110 85 6. Optical proximity sensors 6.4.2 Technical characteristics
The table below lists the key technical data relating to diffuse sensors. The figures
listed in this table are typical examples and merely provide an overview. Parameter Value Object material any Operating voltage 10 – 30 V DC or
20 – 250 V AC Sensing range 50 mm – 2 m (usually adjustable) Switching current (transistor output) 100 – 500 mA Sensitivity to dirt sensitive Life cycle long (approx. 100 000 h) Switching frequency 20 – 2000 Hz Design cylindrical, block-shaped Pro...
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- Spring '12