The phrase "a device that detected" is correct and usable in written English.
It can be used when describing a device that has the capability to sense or identify something, typically in a technical or scientific context.
Example: "The research team developed a device that detected changes in temperature with high accuracy."
Alternatives: "an instrument that identified" or "a tool that sensed".
The automatic reflective diagnosis system (ARDK) is a device that detects human bioenergy through measuring skin conductance at 24 special acupoints on the wrists and ankles.
A "heat detector" is a device that detects heat and sets off the alarm.
A "smoke detector" is a device that detects smoke and sets off the alarm.
The positioning of one or several stimulus objects in a window near the subject's hand is controlled by a photoelectric device that detects periodic openings in the conveyor belt.
Developed by a team at the University of Colorado at Boulder and the National Institute of Standards and Technology, a laser device that detects molecules in one's breath that may hint at diseases.
A small device that detects motion by sensing the user's natural hand movements, Leap Motion allows Fujimoto to manipulate the beat with his mouth and his hands (see video below).
Instead of having their bumps "read" during a Victorian parlor game, people lie down and put their heads inside a powerful magnet device that detects certain molecules in blood flowing through the brain.
Wii Fit Plus makes use of the innovative Wii Balance Board™ accessory, an easy-to-use device that detects players' movements as they enjoy games like Obstacle Course and Perfect 10.
MOST people have smoke alarms, many have carbon-monoxide detectors, and a good number even have devices that detect flooding or unexpected changes in temperature.
Cell phone discouragement also takes the form of posted signs restricting their use, walls and ceilings with metal mesh to block the signals, and devices that detect and warn people of a phone's presence.
