Which of the following is NOT a type of motion detector?

Question

Options

• APhotoelectric sensor
• BPassive infrared sensors
• CMicrowave Sensor.
• DUltrasonic Sensor.

• A
  89% (41)
• B
  4% (2)
• C
  4% (2)
• D
  2% (1)

Explanation

Photoelectric sensors detect the interruption or reflection of a light beam; they are classified as intrusion or presence detectors, not motion detectors. True motion detectors sense movement through a volume of space: Passive Infrared (PIR) sensors detect changes in infrared heat signatures, microwave sensors emit microwave pulses and detect Doppler shifts from moving objects, and ultrasonic sensors emit sound waves and detect reflected frequency changes. Photoelectric sensors trigger on beam-break events rather than actual motion within a detection zone.

No community discussion yet for this question.