A device that displays alcohol-related readings when you blow into it can record several kinds of information, such as whether sampling finished, whether a reading was displayed, and whether an error or warning appeared along with it. Here, mouth alcohol means alcohol that may remain in the mouth after a drink or the use of a household product. To review whether it affected a test, you need to look not only at the number displayed but also at the situation just before the test and how the device completed the sampling process.
A device fault is a state that requires further checking of which part of the device's operation had a problem, such as the sensor, sampling, power, or display. A single displayed result tells you the result at that moment, but it does not sort the cause into an effect of residue in the mouth or a problem with the device. So it is hard to separate the two conclusively from one result. You need to record the screen and the test situation separately and then review each as a different question.
A number is a result, not a cause
The fact that a reading differs from what you expected is not enough to determine the cause. If an oral hygiene product or another household product was used before the test, that can be a clue for reviewing mouth alcohol effects. But the fact that it was used does not prove that the product caused the result.
For the same reason, you cannot declare a sensor fault or a broken device from a single unfamiliar reading. Documents such as OIML R 126-1:2021, which covers the metrological and technical requirements for quantitative evidential breath analyzers, deal with the conditions a device must meet. That does not mean these requirements let every device automatically determine whether an individual test was affected by mouth alcohol.
You also need to distinguish a completed result with a displayed reading from a test that was interrupted. Even if a number appeared on the screen, if there was no indication that sampling was complete or an error message appeared with it, that information must be kept separately from the concentration value. If you compare only the numbers and leave out whether the test was completed, the review of mouth alcohol effects and the review of device operation can become mixed from the start.
Record the screen and the pre-test situation separately
When reviewing a single result, what you need first is not a guess at the cause but facts that can be checked again. Record the reading, unit, and on-screen message as close as possible to how they appeared, without changing them from memory. If you were able to take a photo, linking it to that test entry helps when you need to check the on-screen wording again.
| What to separate | What to record | Why it is needed |
|---|---|---|
| Displayed result | Reading, unit, warning or error message | To avoid confusing the number with device messages |
| Sampling process | Whether the test completed, when it stopped, on-screen messages | To separate completed tests from incomplete ones |
| Pre-test situation | Name of the product used, the general circumstances of use | To review the possibility without concluding it was the cause |
| Device status | Model identification, power warnings, service alerts | To keep clues for a separate review of device status |
For the pre-test situation, it is best to note only that a product was used and the general context of when it was used. A single screen result gives you no basis for guessing the product's ingredients or calculating how much a particular ingredient may have affected the result. On the other hand, if you leave out the fact that a product was used altogether, you lose the starting point for reviewing a possible mouth alcohol effect.
Mouth alcohol effects and device status are different questions
When reviewing mouth alcohol effects, the questions concern the situation before and after the test. They include which product was used, whether the pre-test preparation steps in that model's user manual were followed, and whether sampling was completed. This is not a process of confirming a particular product or a person's physical condition as the cause.
When reviewing device status, you look at the information the device actually showed. You need to know whether there were power warnings, service alerts, repeated error messages, or indications that sampling was incomplete, along with the device model information. The fact that the same reading was displayed is not enough to judge whether the sensor or the display function is working normally.
The two reviews can be kept in one record, but their conclusions must not be merged into one. Using a product before the test does not mean the device is faulty, and the absence of a device warning is not grounds for ruling out a mouth alcohol effect. This is because each possibility needs different information to confirm.
What to check in a hypothetical case
As a hypothetical case, suppose a worker used an oral hygiene product, then took a test and saw a result different from usual. At the observation stage, record separately the product used, roughly when it was used, the reading and unit on the screen, the test completion indication, and whether there was an error message. Statements such as "it read high because of the oral hygiene product" or "the device is broken" are interpretations, not observations, so keep them apart from this record.
A possible action in this case is to compare the pre-test preparation and sampling procedure in that model's manual with what actually happened. Next, check whether there was a power warning or service alert on the screen. If there was an error message or a device status alert, you can consider bundling the original screen information with the model identification and passing it on through the technical support or maintenance channel.
The completion criterion for this review is not getting a lower reading. It is a state in which the screen information from the first result, whether the test completed, the pre-test situation, and the device warning status are all recorded, so that the possibility of a mouth alcohol effect and the device status can each be reviewed. With this criterion in place, repeat test results can also be treated as additional review material rather than numbers that overwrite the first result.
Do not erase the cause with a retest
When a result is in doubt, a repeat test is not a procedure for finding the reading you want or for invalidating the earlier result. First, check the preparation method, sampling method, and meaning of error indications set out in that device's user manual. If you set times or actions not in the manual as if they were solutions, guesswork rather than a review of the actual procedure ends up driving how the result is interpreted.
If device status alerts or error messages keep appearing, do not pass on only the reading. Pass on the on-screen wording, the step at which the test stopped, and the model information together. Conversely, even for a result completed without errors, if there are unconfirmed factors in the pre-test situation, keep those factors as they are to define the scope of follow-up review. This process is not about deciding when a person can drive or making a legal determination. It is about reducing the technical uncertainty around the test result.
A single result is not enough to separate mouth alcohol effects from a device fault conclusively. However, if you record the reading and wording on the screen, whether sampling completed, the pre-test product use, and device warnings separately, confirmed facts and unconfirmed causes stay distinct. That distinction lets you avoid rushing to classify a result as normal or invalid, and lets you move on to checking against the manual and reviewing the device status.
