What Is a Heat Detector?

A thermal detector is a detector that uses a detection element to absorb the incident infrared radiation energy and cause a temperature rise. Based on this, various temperature effects are used to convert the temperature rise into electricity.

The object absorbs radiation, the lattice vibration intensifies, the radiant energy is converted into thermal energy, and the temperature increases. As the temperature of the object rises, temperature-related physical properties change. The phenomenon that an object absorbs radiation to change its temperature and cause the physical and mechanical properties of the object to change accordingly is called

The basic working principle of the thermal detector is that the target infrared radiation is irradiated onto the sensitive material of the detector through the infrared objective lens, causing some measurable physical quantities of the sensitive material to change, so that the change of the measurable physical quantity is read out and converted by A / D Becomes

Thermal detectors are often divided into four types: pneumatic detectors (Galleries), thermocouples or thermopile, thermistors, and pyroelectric detectors.

1. Pneumatic detector

Using the principle of gas volume expansion of the temperature rise of the gas-filled container after receiving heat radiation, the change of the container wall is measured to determine

Compared with various optoelectronic devices, thermal detectors have the following characteristics:

The response rate is independent of the wavelength and belongs to a non-selective detector;

Constrained by the thermal time constant (thermal inertia), the response speed is relatively slow;

The detection rate of the thermal detector is lower than the peak detection rate of the photon detector;

Can work at room temperature. ^[2]