Performance Evaluation of Two Wet Bulb Globe Temperature Equipment for Heat Stress Assessment in Hot/Dry and Hot/Wet Conditions Publisher



Dehghan H¹ ; Shakerian M¹ ; Khodarahmi B¹ ; Habibi P¹ Show Affiliations
Source: International Journal of Environmental Health Engineering Published:2014

Abstract

Aims: The purpose of this study was to compare performance of two these WBGT measuring devices. Materials and Methods: This study was performed in the climatic chamber located in Health School of Isfahan University of Medical Science. The WBGTCasella and the WBGTModel 686 were placed a wide range of hot/dry (28.5-38.5°C) and hot/ wet conditions (25.9-37.7°C) in 3 air flow velocity (0.16, 0.27, 0.31 m/s) for 10 h in the climatic chamber. Wet bulb temperature (tnw), the dry temperature (ta), the globe temperature (tg) and the WBGT were measured every 3 min for both instruments in the total period. The data obtained were analyzed by descriptive method, T-paired test and Regression analysis. Results: The result of this study showed that there were statistically significant differences in the meteorological parameter (tnw, ta, tg, WBGT) obtained from the WBGTCasella and WBGTModel 686 (P < 0.001). A high correlation also was seen between the values obtained by the WBGTCasella and the WBGTModel 686 (r = 0.993). Furthermore, there were statistically significant differences in the air flow velocity parameter (0.157 m/s) and (0.27 m/s) and (0.314 m/s) in a hot/ dry (r = 0.994) and (0.980) and (0.994) respectively. There were statistically significant differences in the air flow velocity parameter (0.157 m/s) and (0.27 m/s) and (0.314 m/s) in a hot/wet (r = 0.980) and (0.992) and (0.973) respectively. Conclusion: Since there is a high correlation between the values recorded by two devices and a remarkable cost — efficacy of WBGTModel 686, using WBGTModel 686 is an acceptable method for measuring the heat stress if the prediction equations are utilized. According to the different temperature conditions, was obtained dry temperature, wet temperature and globe temperature both devices measurement in different climatic conditions equation WBGTCasella = 2.04 + 1.03 (WBGTModel 686). About 2 units WBGTModel 686 lower than the WBGTCasella and recommend the measures to be considered in this case as well as the manufacturers also, recommend doing that the reform of sensor measurements and the calculation methods. © 2014 Dehghan H. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.