An evaluation of several wet bulb globe temperature algorithms at Dugway Proving Ground

The Wet Bulb Globe Temperature (WBGT) is a standard heat-stress measure used by the U.S. Army. The parameter is created by arithmetic combination of measurements from standard air-temperature sensors, black globe temperature sensors, and natural wet bulb temperature sensors. The natural wet bulb sensor requires, especially in the desert environment, nearly daily maintenance to fill the reservoir and to change the wick. As a result, only one or two locations around the test range can have an in situ direct measurement of the WBGT. Test and training activities occur at many locations, so a calculation of the WBGT, using standard meteorological variables, is required.

Hunter and Minyard (1999) developed an algorithm to compute the WBGT using standard meteorological variables at the Savannah River Site located in southern South Carolina. An evaluation of the Hunter and Minyard algorithm found that the equations developed for the southeastern U.S. are not directly applicable to the western deserts. Using data from several years of WBGT measurements at DPG, multiple linear regression is used to generate a set of predictor equations for the WBGT. Additional data from White Sands Missile Range in New Mexico is incorporated to improve the predictor equations. While the linear regression developed at DPG predicts well across a full range of temperatures, it does not achieve the operationally required level of accuracy for the critical high-temperature range.