backupsensor
nounUK /ˈbækʌp ˌsɛnsə/
US /ˈbækʌp ˌsɛnsər/
A backup sensor is a helper that tells you when something is behind your car.
The backup sensor beeped when I got too close to the trash can.
OTHER MEANINGS
2. A second sensor that takes over if the main one stops working.
The robot switched to its backup sensor when the first one broke.
3. A device that saves a copy of sensor readings for later use.
The backup sensor stored the temperature data overnight.
4. A spare part kept ready to replace a damaged sensor.
He grabbed a backup sensor from the toolbox to fix the machine.