Breathalyser Calibration FAQs

Breathalyser calibration is an important part of keeping and maintaining a breathalyser. No matter what breathalyser you have and what technology it uses, it will require regular calibration to maintain its accuracy.

In this post, we answer some frequently asked questions about breathalyser calibration.


What is calibration?

Calibration is checking and adjusting a measuring instrument by comparing it with an accepted model. In the case of breathalysers, a known and accurately maintained gas concentration (for example, 0.05%BAC) is blown into a breathalyser, and the unit is adjusted to make sure it accurately reads the correct BAC level.

Why does my breathalyser need calibration?

Calibration is necessary for any measuring tool. When you use something so many times, it will lose some of its accuracy over time, and the same goes for breathalysers. Calibrating your breathalyser regularly ensures that it is inspected professionally to maintain its accuracy.

Does my breathalyser calibration include normal repair?

Breathalyser repair is not covered under the calibration cost. An extra cost will be involved in repairing a damaged or faulty breathalyser.

How often should I calibrate my breathalyser?

The more you use your breathalyser or the more alcohol it’s been exposed to, the sooner you will need it to be calibrated. The calibration period depends on the number of uses and the type of sensor in the breathalyser.

Personal breathalysers usually use semiconductor sensors and will require calibration every 6 months or 200 uses. Industrial breathalysers usually use fuel cell sensors, which maintains its accuracy for longer, and requires calibration less frequently – every 12 months or about 500 uses, depending on the model.

Improper usage can lead to your breathalyser requiring calibration sooner or immediately. Spit, moisture (from not keeping the breathalyser protected properly), or blowing into a breathalyser without waiting for 20 minutes after eating or drinking can damage the sensor. In this case, the breathalyser would require calibration earlier or immediately.

If I’m not using my breathalyser, why do I need to calibrate it?

Breathalysers are like cars – you cannot expect it to work perfectly if you use it for the first time after several months of keeping it untouched. If you haven’t used your breathalyser for a long period of time, you will probably need to have it calibrated before using it to ensure that it is accurate.

I have more than one breathalyser and each one gives me a different reading. Why is that?

The usual belief is that the more expensive a product, the better it is. This is not truly the case when it comes to breathalyser accuracy. All breathalysers must be calibrated regularly to maintain its accuracy. If you have more than one breathalyser and each one gives you a different reading, it usually means that one or more of your breathalysers need calibration.

The breathalyser count down is slow. Does it mean my breathalyser needs calibration?

If the breathalyser count down is slow, it means either that the battery is low or that the sensor needs time to warm up. This is normal. Once the sensor warms up, the count down time is usually faster, as you will notice if you re-use your breathalyser for sequential readings.

I’ve had more than a few drinks but the breathalyser reading is lower than expected. Is something wrong with my breathalyser?

The common misconception among customers is that if you drink 2-3 glasses of alcohol, the breathalyser should definitely get a reading. In actuality, your BAC reading will depend on your age, gender, and size as well, and not just the number of drinks that you have had.