Translation guide
A device or instrument that detects or senses something. The most common Japanese equivalent is 検出器 (kenshutsuki) for technical/scientific contexts, but the choice depends on what is being detected.
A device that detects physical quantities, signals, or substances.
General term for a detector in scientific and engineering contexts. Used for detecting light, radiation, gas, etc.
この検出器は微量のガスも感知します。
This detector can sense even trace amounts of gas.
Common loanword for 'sensor'. Often used in consumer electronics and everyday tech.
スマートフォンには多くのセンサーが搭載されています。
Smartphones are equipped with many sensors.
Often used for detectors that locate or find something, like metal detectors or mine detectors.
空港で金属探知機を通過しました。
I passed through a metal detector at the airport.
Used for devices that sense or perceive, such as fire or smoke detectors. More common in safety equipment.
火災感知器が作動しました。
The fire detector activated.
Common compound words for specific types of detectors.
Metal detector.
ビーチで金属探知機を使っています。
I'm using a metal detector on the beach.
検出器 (kenshutsuki) is the most general and technical. 探知機 (tanchiki) implies searching/locating (e.g., metal detector). 感知器 (kanchiki) is often used for safety devices that sense environmental changes (fire, gas).
センサー (sensor) is widely understood and used in consumer products. For technical writing, 検出器 is preferred.
Smoke detector.
煙感知器の電池を交換してください。
Please replace the battery in the smoke detector.
Radiation detector.
放射線検出器で測定しました。
We measured it with a radiation detector.
Lie detector (polygraph).
嘘発見器は裁判では証拠として認められないことが多いです。
Lie detectors are often not admissible as evidence in court.