How Do Heat Sensors Work?

What Does a Heat Sensor Do?

All objects emit infrared (IR) radiation. While invisible to the naked eye, this "heat radiation" can be observed through the use of specialized equipment. A heat sensor passively collects infrared data and analyzes it.

How Does it Work?

A heat sensor works by using pyroelectrical materials, which emit electrical impulses when heated or cooled. IR radiation passes through the front of the device and comes into contact with a set of sensors made of pyroelectrical plate, crystal or film. The electrical impulses from the sensors is then collected and electronically turned into usable data.

Thermal imaging and infrared vision uses thermal-sensitive photodiodes to detect and process IR radiation. However, these are strictly speaking not heat sensors, but are instead vision devices such as night vision aids or thermographic cameras.

What Are IR Sensors Used For?

Heat sensors are used in devices such as passive motion detectors, or the heat seekers in certain types of missiles. Thermal imaging is used in Forward Looking Infrared (FLIR) sensors, certain (but not all) night vision instruments, and thermographic cameras.