infrared sensor
nounUK /ˌɪnfrəˈred ˈsensə/
US /ˌɪnfrəˈred ˈsensər/
A device that can feel heat or see things in the dark.
The robot uses an infrared sensor to avoid bumping into walls.
OTHER MEANINGS
2. A component in a TV remote that sends invisible light signals.
The infrared sensor on the TV picks up the remote's signal.
3. A safety device in a garage door that stops it from closing on people.
The garage door's infrared sensor stopped it when my dog ran under it.
4. A part of a phone or camera that helps it sense heat or distance.
The phone's infrared sensor helps it focus in low light.