Parameters of thermal vision devices

Thermal infrared detector

Infrared Detector is a device that converts Infrared radiation signals into electrical signals output.

Detector resolution—Thermal infrared detector is the core component of thermal imager. The higher the resolution, the better.It is directly related to the effective resolution and imaging effect of the final thermal image. However, due to the limited technology, the resolution of thermal infrared detector is much lower than that of the ordinary camera CCD/CMOS, which is millions of pixels or even tens of millions of pixels.

Detector type—Vanadium oxide and amorphous silicon are two main technologies of uncooled infrared detectors in civil market.

Thermal sensitivity (NETD)

NETD is an objective evaluation index of the sensitivity of thermal imaging system, which can be used to predict the detection distance of targets with small temperature difference.The refrigerated type of infrared detector NETD can be less than 30mK, the high-grade unrefrigerated type of infrared detector NETD can be less than 50mK, and the mainstream entry-level low-priced unrefrigerated type of infrared detector NETD is mostly in the level of 100 ~ 150mK.The mK unit here is one over one thousand “kelvin” temperature unit, 50 mK is equivalent to 0.05 ℃.

Temperature range

Different thermal imagers are designed to measure different temperature ranges.Mainstream products for – 20 ~ 120 ℃.

Image capture frequency

The refresh rate of thermal image display is closely related to the image processing performance in the circuit. The common frame frequencies are 9Hz, 30Hz, 60Hz and 120Hz.