Bump Testing vs. Full Calibration: What's the Difference?

These two terms get used interchangeably, and that's a mistake — they check different things.

Bump test

A bump test is a quick pass/fail check: you expose the sensor briefly to a known concentration of gas and confirm the alarm triggers and the reading responds. It doesn't correct anything — it just confirms the detector is alive and responsive. Because it takes seconds and needs minimal gas, ISEA recommends doing this before every day the detector is used.

Full calibration

Calibration is the process of actually adjusting the sensor: exposing it to a zero-gas (clean air) reference, adjusting the reading to zero, then exposing it to a known concentration of the target gas and adjusting the reading to match. This corrects for the gradual drift that happens as sensors age and get exposed to their environment.

Why both matter

A sensor can pass a bump test (it responds to gas) while still being out of calibration (the exact reading is off). Relying on bump tests alone can leave you with a detector that alarms, but at the wrong concentration. Relying on periodic calibration alone means a dead sensor could go unnoticed between cycles. Use bump testing as your daily gut-check and full calibration as your scheduled correction.

Same gas source, same generator — GoACD's calibrators are built to handle both. See how calibration works.