BreathKey Calibration

Calibration is the checking and regulation of the precision of a unit by comparing its results with a known value.  For example, a known 0.080% alcohol gas content is blown into a breathalyzer, and the unit is adjusted to make sure it reads precisely 0.080 %BAC (blood alcohol content).

Over time the breathalyzer alcohol sensor can lose accuracy.  All breathalyzers, including the BreathKey, must be recalibrated periodically so that they will maintain their accuracy. The BreathKey should be calibrated every six months to one year, or whenever you think that you are getting inaccurate results.

See the calibration section of our support page for more about the calibration fee and the shipping address.

If the BreathKey is maintained properly and calibrated on a regular basis, its accuracy will be ±.010% BAC at .080% BAC.  This means that on average the BAC reading from the BreathKey will be within .010% of your true BAC level, if your true BAC level is .080%.

While the legal limit is .08% BAC (blood alcohol content), impairment can begin at a level of .04% or even lower.  Everyone responds differently to alcohol; some people may be reasonably safe at a lower BAC level while others may not.  A precaution when using any breathalyzer is to consider what your personal limit may be as well.  Intoxication can occur almost immediately and also progress over several hours of drinking.

For these reasons the BAC results from the BreathKey or from any breathalyzer cannot be used on their own to determine whether or not you are impaired or if you are safe to drive.  Only you can make that determination.

In addition, no breathalyzer can assure that you will not get arrested for driving under the influence of alcohol.  You can be arrested for DUI with a BAC that is less than the legal limit.  Impairment can occur at any point during drinking depending on the individual.

For these reasons it is always safest when you do not drink and drive.