Calibration checks are performed to verify instrument accuracy and are conducted how often?

• A. A test to verify instrument accuracy; performed before, during, and after sampling, typically at start and end of sampling period.
• B. A test to adjust battery performance.
• C. A test to calibrate PPE fit.
• D. A test to measure ambient temperature.

Answer: (A)

Calibration checks verify that an instrument’s readings are accurate. Because instruments can drift over time due to sensor aging, temperature changes, or battery issues, it’s important to check accuracy at multiple points. Performing checks before sampling confirms the device starts operating within tolerance, doing them during sampling helps catch drift as it happens, and checking after sampling verifies the final reading is still valid. This comprehensive approach ensures the data collected are reliable and defensible.

The other options aren’t about confirming measurement accuracy: adjusting battery performance relates to power, calibrating PPE fit is about protective equipment fit, and measuring ambient temperature is about environmental monitoring—not about verifying the instrument’s accuracy against a known standard.