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Unformatted text preview: Minimum distances between ultrasonic proximity sensors and a lateral, reflecting wall 7.3.2 Required minimum size of the object
The required object size depends on the acceptance angle of the ultrasonic beam. If
the ultrasonic sound waves travel past an object which is too small, then any objects
which may be alongside or in the background may interfere. As there is often
insufficient data provided by the manufacturer, a preliminary test is recommended
by moving the test plate from the side towards the object to be detected whilst
observing the switching distance. 1 2 3 Ultrasonic sensor (1) Sound cone (3) Acceptance angle of sound cone (2) 4 Object (4) Fig. 7.3.1: Detection area of an ultrasonic sensor 112 © Festo Didactic GmbH & Co. KG • FP 1110 7. Ultrasonic proximity sensors 7.3.3 Type of object
Suitable are solid, fluid, pulverised or granulated materials. Unsuitable for
ultrasonic sensors are ultrasound absorbing materials such as coarse clothing
material, cotton wool, terry cloth, foam rubber, rock wool. On the other hand, it is
possible to detect these materials by m...
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- Spring '12