1. one that detects, especially a mechanical, electrical, or chemical device that automatically identifies and records or registers a stimulus, such as an environmental change in pressure or temperature, an electric signal, or radiation from a radioactive material.

1. A device capable of registering a specific substance or physical phenomenon.

1. one who, or that which, detects; a detecter.
2.
3. an indicator showing the depth of the water in a boiler.
4. A galvanometer, usually portable, for indicating the direction of a current.
5. any of various devices for detecting the presence of electric waves.

1. one who or that which detects or brings to light; one who finds out what another attempts to conceal; a revealer; a discoverer.
2. an instrument or a device for indicating the presence or state of a thing.
3. sometimes written detecter.

1. electronic equipment that detects the presence of radio signals or radioactivity
2. any device that receives a signal or stimulus (as heat or pressure or light or motion etc.) and responds to it in a distinctive manner
3. rectifier that extracts modulation from a radio carrier wave