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Unformatted text preview: g as a sufficiently high percentage of the light beam is definitely reflected.
• Whereas with through-beam sensors objects can only be detected laterally to the
light beam, diffuse sensors allow frontal detection, i.e. in the direction of the
• Depending on the setting of the diffuse sensor, objects can be detected
selectively in front of a background. Disadvantages of a
diffuse sensor • The response curves according to Fig. 6.4.2 are not completely straight.
Therefore, diffuse sensors are not as suitable as through-beam sensors, if
accurate lateral response is crucial. Notes • The size, surface, shape, density and colour of the object determine the intensity
of the diffused light emission and hence the actual sensing range. The nominal
sensing range given in data sheets is measured using the white side of the
standard Kodak test card. The background must absorb or deflect the light
emission, i.e. in the absence of an object, the reflected light emission must be
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This note was uploaded on 11/01/2012 for the course CHEMICAL 102 taught by Professor Jamesrodriguez during the Spring '12 term at Universidad Politécnica de Cartagena.
- Spring '12