Why calibration matters (and when to do it)

Every breathalyser sensor drifts slightly with use and age — fuel-cell sensors more slowly than semiconductor ones, but both drift eventually. A device that reads accurately out of the box won’t necessarily read accurately a year of regular use later.

What drift looks like

Drift usually shows up as a device reading slightly low or slightly high compared to a known reference, not as an obvious fault. That’s what makes it easy to miss without periodic checking.

A general guide

• Light, occasional use: recalibrate roughly once a year
• Regular or professional use: every 6 months
• After any hard knock or drop: check sooner rather than later

Your device’s manual will have a specific recommendation — follow that over any general rule.

This article is general information, not medical advice.