4.4 SUMMARY

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Sourcing sensors allow current to flow out from the V+ supply.

Sinking sensors allow current to flow in to the V- supply.

Photo-optical sensors can use reflected beams (retroreflective), an emitter and detector (opposed mode) and reflected light (diffuse) to detect a part.

Capacitive sensors can detect metals and other materials.

Inductive sensors can detect metals.

Hall effect and reed switches can detect magnets.

Ultrasonic sensors use sound waves to detect parts up to meters away.