1. (noun) 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

• detector
• sensing element

1. (noun) 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

• device

1. (noun) 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

• electric eye
• magic eye
• photocell
• photoconductive cell
• photoelectric cell
• metal detector
• mine detector
• trace detector

1. (noun) 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

• detect
• discover
• find
• notice
• observe
• feel
• sense