Yes, DETECTORS is a Scrabble word!

Letter values in Scrabble US: D 2, E 1, T 1, E 1, C 3, T 1, O 1, R 1, S 1.

Is it a valid word?

DETECTORS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

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
rectifier that extracts modulation from a radio carrier wave
electronic equipment that detects the presence of radio signals or radioactivity

Also: sensing element.