Which variable is the ambient air temperature measured with a thermometer shielded from radiant heat?

• A. Dry bulb temperature
• B. Radiant temperature
• C. Humidity
• D. Metabolic rate

Answer: (A)

The ambient air temperature measured by a thermometer shielded from radiant heat is the dry-bulb temperature. This reading reflects the actual air temperature around the person, because the shield blocks radiant heat from sources like the sun or hot equipment while still letting air circulate to the sensor. Radiant temperature, by contrast, is what surfaces feel like due to radiant heat and is measured with a globe thermometer; humidity is a moisture property of the air and is measured separately (hygrometer); metabolic rate is about the heat produced by the body. So, shielding the thermometer from radiant heat yields the dry-bulb temperature.