Where must the wet bulb, dry bulb and resultant effective temperature be measured and recorded as often as necessary?

• A. The main intake near surface
• B. The goaf area
• C. The surface weather station
• D. Each coal face where mining operations are taking place

Answer: (D)

Assessing the thermal environment in a coal mine hinges on measuring the conditions where people are actually exposed to heat. The wet-bulb and dry-bulb temperatures are used together to derive the resultant effective temperature, which reflects how hot the air feels when humidity is a factor. Because conditions can vary dramatically from one location to another, readings must be taken at each coal face where mining operations are taking place to capture the true exposure workers experience. This localized data is essential for guiding ventilation adjustments and ensuring safety. Taking measurements at the main intake near the surface or at the surface weather station wouldn’t reveal the hot or humid spots miners face at the face, and checking only the goaf area wouldn’t reflect the conditions where people are actively working. Therefore, measurements should be made and recorded at each coal face where mining is occurring, as often as necessary to monitor changes and protect workers.