Which thermometer type is used for non-contact measurement of surface temperatures?

Which thermometer type is used for non-contact measurement of surface temperatures?

• A. Bimetallic Stemmed Thermometer
• B. Dial Thermometer
• C. Candy Thermometer
• D. Infrared Thermometer

Answer: (D)

Infrared thermometers measure surface temperature without touching the object by detecting the infrared energy it emits. This non-contact capability makes them ideal for hot, moving, or contamination-sensitive surfaces, where touching the item isn’t practical or safe. The other common types rely on direct contact with the surface to sense temperature: a bimetallic stemmed thermometer uses a metal probe that must touch, a dial thermometer’s probe is pressed against or inserted into the surface, and candy thermometers sit in the hot mixture but still require contact. Infrared thermometers give a quick, distance-based reading, though accuracy can be affected by surface emissivity and proper aiming.

Infrared thermometers measure surface temperature without touching the object by detecting the infrared energy it emits. This non-contact capability makes them ideal for hot, moving, or contamination-sensitive surfaces, where touching the item isn’t practical or safe. The other common types rely on direct contact with the surface to sense temperature: a bimetallic stemmed thermometer uses a metal probe that must touch, a dial thermometer’s probe is pressed against or inserted into the surface, and candy thermometers sit in the hot mixture but still require contact. Infrared thermometers give a quick, distance-based reading, though accuracy can be affected by surface emissivity and proper aiming.