Abstract: In terms of the famous Beer's principle, a cosine relationship between the distribution of heat radiation of an object to the surrounding space and its radiation direction has been confirmed. Consequently, an obvious difference to the amount of the received infrared radiation is ubiquitous and even results to the error of infrared radiation temperature measurement, owing to the nature of the relative position relationship between the measured target and the detector. To address the issue, the relation of target position to the angle coefficient of detector was firstly characterized quantitatively. A modified model of the amount of infrared radiation was subsequently proposed. Through the modified model, a quantitative compensation scheme for the amount of detector radiation was implemented from target radiation. Moreover, to test the reliability of the method proposed above, an experiment measurement to derive the amount of radiation from uniform light was carried out by using the infrared detector. The results showed that , as the relative angle between the detector and uniform light increases, the gray values from the measurement of detector to uniform light under different ?-angles remarkably decreases. Also, the relative error is lower than 0.04 after the quantitative compensation for the measurement of detector. The present optimized method does not improve the accuracy of infrared radiation temperature measurement, but also enhance the stability of test technology. Such a method can provide a guidance for the error correction of infrared radiation temperature measurement.

Key words: angle coefficient, Beer's principle, heat radiation, the least square method