Function check (bump tests) verifies the instrument calibration by exposing it to known concentrations of __________.

• A. Calibrants
• B. Reference gas
• C. Test gas
• D. The environment

Answer: (C)

A bump test checks whether the detector actually responds when exposed to gas by using a known concentration of gas called a test gas. The idea is to confirm the sensor will detect the target gas and trigger alarms within the expected time, ensuring the instrument is functioning properly between calibrations. This is different from calibration, which uses calibration (calibrant) gas or a reference gas to adjust the readings to match a known standard. The environment isn’t used for this purpose, since a bump test is about verifying the sensor’s ability to respond, not adjusting its measurement.