Accurate measuring temperature with infrared thermal imager in the unstable condition of ambient temperature

The infrared thermal imaging systems are widely used for distinguishing target radiation temperature difference and they can also be used to measure the absolute temperature of the target. There may be great difference between the true value and the measurement results in the actual application of the infrared thermal imaging systems, just because of the unstable condition and the lack of compensation of the imager's own heat radiation. In order to obtain the accurate temperature of the target in some special conditions, such as aircraft internal and pilotless platform, we present a stationary infrared thermal imaging system to gather the goal gradation images and a method to compensate the influence of the imager's own heat radiation and the unstable condition. In radiation calibration experiment, we establish corresponding relationships between the gradation difference and the temperature difference by using a goal blackbody and a cooperation calibration blackbody between 0°C and 150°C. We also analysis the relationships mentioned above under the normal temperature and the high temperature separately. The results show that the proposed method may be useful in increasing the temperature measurement precision