Which of the following is a correct statement about infrared tester use?

• A. It Should Be Allowed To Adjust To Ambient Temperature Changes
• B. It Must Be Recalibrated Daily
• C. It Cannot Measure Distant Objects
• D. It Requires Direct Contact With The Surface

Answer: (A)

Infrared testers infer surface temperature from the infrared energy a surface emits. That energy, and thus the reading, is influenced by the sensor’s own temperature and by ambient air temperature. To keep readings accurate across changing environments, the device should be able to adjust for ambient temperature changes, either automatically or through a user-compensating setting. This is why allowing ambient-temperature adjustment is the correct statement.

The other ideas don’t fit typical use: daily recalibration isn’t normally required—most IR testers are factory calibrated and only need periodic checks as needed by the work environment; infrared testers can measure objects at a distance depending on the device’s optical design, so they’re not limited to near targets; and they are designed for non-contact measurement, so they do not require direct contact with the surface.