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Calibration FAQ


How does a breathalyser work?
Once alcohol has been absorbed into your bloodstream, it is evaporated into your exhaled breath through blood capillaries in your lungs. This is how the breathalyser can read your BAC through your breath. For the most accurate reading the breathalyser will need a deep lung sample of your breath, this is why you are required to exhale your breath for a certain amount of time for higher quality samples.
Why do I need a breathalyser?
Breathalysers are handy for anyone who consumes alcohol. Quite often people are not aware exactly how much alcohol they can consume and still be under the legal limit. There are different factors that can affect a persons BAC as well as the rate the alcohol is absorbed into your bloodstream. These factors include food and drink, smoking and weight. A person may seem to be sober but that does not mean they are under the legal limit.

What's the difference between Semi-Conductor and Fuel Cell Breathalysers?
There are two types of breathalysers on the market, traditional units with semi-conductor sensors and higher accuracy units with fuel cell sensors.

Australian Police are using fuel cell sensor breathalysers and have been for some time. One of the reasons for this is that fuel cell sensors last longer then semi-conductor sensors, allowing more accurate readings before the sensor needs to be recalibrated or replaced. Please see below more information regarding the differences between these two technologies.

Advantages of Semi-Conductor Breathalyzers:

  • An economical method to determine blood alcohol level, keeping the cost of the unit lower.

  • Semi-conductors are accurate and very sensitive to any chemical substances.

  • Ideal for personal breathalyzers and for low-volume professional testing.

Disadvantages of Semi-Conductor Breathalyzers:

  • Accuracy declines after 250-350 uses or 6 months, after which the unit must be calibrated or have the sensor replaced.

  • Sensors can decrease in accuracy even when not in use.

Advantages of Fuel Cell Breathalysers:

  • Fuel cell breathalysers are more accurate, detecting blood alcohol reading to 3 decimal places.

  • Reduces false readings from substances such as ketones that are similar in chemical structure to alcohol.

  • Calibration lasts 3-5x longer than Semi-Conductor Breathalysers.

  • Accuracy does not deteriorate when the unit is not in use.

  • Gives the user 700-1000 uses before calibration needed.

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.
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.
How much does calibration cost?
Please refer to the table below for what calibration pricing applies to your breathalyser.
Service Type Calibration Fee Calibration Certificate
$45 $35
$90 $35
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 use fuel cell sensors and will require calibration every 6 months or 500 uses depending on the model. Industrial breathalysers, to maintain their Australian Standard Certification, must be calibrated every 6 months.
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.
How do I get my breathalyser calibrated?
If your unit needs to be calibrated all you need to do is send your unit back to us at Breathcheck after downloading and filling out a calibration form and we’ll send it back to you as good as new and as quickly as possible.

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