An evaluation of methods for measuring surface temperature

In order to evaluate the effectiveness of infrared camouflage, surface temperatures of targets and backgrounds have to be measured. A variety of instruments are available to do this and have been used in previous field tests. Inconsistencies in the results from these experiments prompted the test reported herein. A simple asphalt target was instrumented with several types of thermometers to measure kinetic temperature and radiation temperature. Readings from radiation thermometers were found to depend on target emissivity, sky temperature, and spectral range of instrument. Measurements of kinetic temperature depended on surface contact of the probe and on the amount of surface disturbance. Any comparison between different temperature measurement techniques should take these influences into account.