Chapter 27 - Mechanical and Proximity Switches

A(n) _____ reflector has a triangular grooved surface that returns a light beam on a parallel axis.

Corner Cube

For a 2-wire AC proximity sensor, power is provided to the L2 (neutral) circuit and the load is in the line to the L1 (hot) terminal.

False

For a retro-reflective mode photoelectric sensor, the sensor is actuated when an object blocks the beam.

False

Mechanical switches cannot be used to explosionproof areas.

False

_____ switches require physical contact with an object to actuate the switch mechanism.

Mechanical

Proximity sensor transitor output circuits are either NPN (sinking) or _____ (sourcing).

PNP

A capacitance proximity sensor acts as a simple capacitor with one plate built into the sensor and the _____ being the other plate.

Target Object

A cylindrical-style proximity sensor is designed with the sensing field at the end of the cylinder.

True

For a 2-wire DC proximity sensor, the load is always in the circuit.

True

_____ proximity sensors function by generating a pulse of sound waves.

Ultrasonic

Ultrasonic proximity sensors have a _____ close to the sensor where a target cannot be detected.

dead zone

A(n) _____ proximity sensor consists of a sensor coil, an oscillator, a trigger circuit, and an output switching circuit.

inductance

A diffused-mode photoelectric sensor detects light _____.

reflected from the target