Think of calibration as a service on your car; if you use the car a lot, you’ll need to have it serviced more often – even if your car just sits in the garage for most of the time, it still needs an annual service. Sometimes, leaving your car out of use can lead to more service work than using it regularly. It’s the same with a breathalyser. Most people will perform less than 500 tests a year, in which case an annual calibration will be fine.
However, if the breathalyser spends long periods of time out of use, this in itself can lead to problems with the sensor drying out. It’s best to use a breathalyser at least a couple of times a month to make sure this doesn’t happen.
Another reason for regular calibration – if a breathalyser hasn’t been recalibrated for some time, it is possible that the sensor will move so far out of range that it cannot be brought back into the operating range. We therefore recommend personal digital breathalysers are calibrated every 12 months or if you’re using it for workplace alcohol testing, every 6 months.
Using a breathalyser within less than the minimum time after drinking (20 mins) or smoking (10 mins) can dramatically reduce a sensor’s life before it needs recalibrating. In some cases the whole device will need replacing if excessive smoke/alcohol or other contaminants have been blown into the unit. It’s worth remembering that breathalysers are sensitive medical instruments and must be used in accordance with instructions supplied in the user manual.