also: せきがいせんセンサ
noun
infrared sensor
A device that detects infrared radiation, used in motion detectors, thermal cameras, and remote controls.
この照明は赤外線センサーで自動的に点灯します。
This light turns on automatically with an infrared sensor.
Standard spelling with long vowel marker.
Variant without long vowel marker, common in technical contexts.
Compound of 赤外線 (infrared rays) and センサー (sensor), a straightforward technical term.