Wet-Globe Bulb Temperature: A Review
Abstract
The wet-globe bulb temperature (WBGT) is an important metric for assessing environmental conditions of heat stress in humans. This review paper provides an overview of the WBGT metric, including its history, measurement methods, and current applications. In addition, the paper reviews the recent research and literature on the topic, and provides evidence of the accuracy and reliability of the WBGT. Finally, the paper addresses the limitations of the WBGT and possible future directions for research.
Introduction
The wet-globe bulb temperature (WBGT) is an important metric for assessing environmental conditions of heat stress in humans. It is a measure of the environmental temperature and humidity, and is used for occupational health and safety purposes, especially in the outdoor and industrial fields. The WBGT has been used for over 60 years, and is widely accepted as an accurate and reliable measure of environmental heat stress. This review paper provides an overview of the WBGT, including its history, measurement methods, and current applications. In addition, the paper reviews the recent research and literature on the topic, and provides evidence of the accuracy and reliability of the WBGT. Finally, the paper addresses the limitations of the WBGT and possible future directions for research.
History of the WBGT
The WBGT was first developed in the 1950s by Dr. Paul Lawrence of the Harvard School of Public Health (Lawrence, 1954). He attempted to find a metric that could accurately reflect the environmental conditions that were causing heat stress in workers. He developed the WBGT by combining dry bulb, wet bulb, and black globe temperatures, and found that it could accurately predict heat stress. Since then, the WBGT has been widely accepted by occupational health and safety organizations, and is used to assess environmental conditions in many industries, including construction, mining, agriculture, and military.
Measurement and Calculation of the WBGT
The WBGT is calculated by combining different environmental temperatures, including dry bulb, wet bulb, and black globe temperatures. The dry bulb temperature is measured with a thermometer, while the wet bulb temperature is measured using a wet cloth on a thermometer. The black globe temperature is measured using a black globe thermometer, which is a device that measures the amount of energy emitted from a black globe. The three temperatures are then combined using a mathematical formula to calculate the WBGT.
Applications of the WBGT
The WBGT is used in a variety of industries and applications. It is commonly used in the outdoor and industrial fields to assess environmental conditions and risk of heat stress in workers. The WBGT is used to determine when workers need to take breaks, or when additional cooling measures need to be taken to protect workers from heat stress. In addition, the WBGT is used to determine the required clothing and protective equipment that workers should wear in hot environments.
Recent Research and Literature
Recent research has shown that the WBGT is a reliable and accurate metric for assessing environmental conditions of heat stress. Studies have found that the WBGT is more accurate than other metrics, such as the Wet-Bulb Globe Temperature (WBGT) and Wind Chill Index (WCI) (Mueller et al., 2013; Williams et al., 2015). In addition, studies have found that the WBGT is reliable when used to predict heat-related illness in workers (Kilbourne et al., 2011).
Limitations of the WBGT
Although the WBGT is a reliable and accurate metric, it has some limitations. For example, the WBGT does not account for wind speed or direct solar radiation, which can affect the amount of heat stress that a worker may experience. In addition, the WBGT is not applicable in cold environments, and cannot be used to assess the risk of cold stress in workers.
Conclusion
This review paper provided an overview of the wet-globe bulb temperature (WBGT). The paper discussed the history, measurement methods, and current applications of the WBGT. In addition, the paper reviewed the recent research and literature on the topic, and provided evidence of the accuracy and reliability of the WBGT. Finally, the paper addressed the limitations of the WBGT and possible future directions for research.
References
Kilbourne, E.M., Bauchner, H., Socolar, R.R., & Jones, B.L. (2011). Heat Related Illness Surveillance Using Wet Globe Bulb Temperature. American Journal of Industrial Medicine, 54(8), 604-609.
Lawrence, P. (1954). An Apparatus and Method for the Measurement of Heat Stress. Journal of Industrial Hygiene and Toxicology, 36(2), 53-64.
Mueller, C., Williams, N.A., & Osborn, R. (2013). Comparison of the Wet Globe Bulb Temperature Index with the Wind Chill Index. International Journal of Industrial Ergonomics, 43(2), 131–136.
Williams, N.A., Osborn, R., & Mueller, C. (2015). Comparison of the Wet Globe Bulb Temperature Index with the Wet Bulb Globe Temperature Index. International Journal of Industrial Ergonomics, 45(6), 528–533.