Abstract
Field experience has shown that, when a sling psychrometer is used in the presence of high thermal radiation flux, the indicated dry-bulb and wet-bulb temperatures may be considerably in error. Tests were made under controlled laboratory conditions to determine the magnitude of the errors which might be expected under various environmental conditions. The results are shown graphically. The effect of these temperature errors on the calculated heat exchange between a workman and the environment has also been investigated and the results are tabulated. The results of a study of the effect of wick length on wet-bulb error due to stem conduction are also included in the paper.