A personal breathalyzer is not just a tool that shows the reading right after a test. It can store previous test results or connect to a smartphone app to manage results. For example, DATECH's AF-40BT offers storage of up to 10,000 test results, Bluetooth smartphone connectivity, and a dual mode that allows use of the device alone or with the app. These features help you look back on your habits, but they also create a risk of reading a previous result left on the screen as one you just took.
Especially when you want to decide quickly whether to drive, such as the day after a company dinner, you need to first determine when a number was produced before looking at the number itself. The fact that you turned on the device, opened the app, or see a reading on the screen does not mean a new test has been completed. It is safer not to use a result whose test time is uncertain as a value that tells you your current state, and to set your travel plans conservatively to reflect that uncertainty.
Stored results and new test results play different roles
The purpose of the storage feature is to keep past results. So looking up a previous result on the device or app must be distinguished from taking a new test. A previous reading is only a record of a test at that time, not a value that stands in for how your body is today.
If a product can be used both in standalone mode and with an app, there are more points of confusion. You need to check separately whether the number you saw on the device screen and the number you saw on your phone are from the same moment, or whether one of them still shows an old record. The record at the top of the app list, or the last screen you opened, does not automatically mean it is the result you just took.
Three things to check before the number
When you see a result, first determine whether the screen is the completion screen of a new test or a screen for viewing stored records. Look at clues you can actually confirm, such as the screen title, whether it is a list of records, and indications of when the result was created. If you cannot pin down the time from what is shown, it is right not to assume it is "the value just measured."
Next, do not decide it is a new result just because you saw the same number while switching between the device and the app. A Bluetooth connection means the device and smartphone can communicate, not a guarantee that everything on the phone screen has just been updated. Only when there is an actual indication in the app that a new result has been reflected should you read it according to what that indication means.
The last is whose result it is. On a device shared by a family, in screen photos in a family group chat, or in an app several people have checked in turn, you also need to separate whose record it is. To avoid reading someone else's previous result as your own, or having a family member take the result you sent yesterday as today's, it is useful to note "who tested and when" with each result, even if not by name.
| What to check | What to actually look at | How to handle an unclear time |
|---|---|---|
| Device screen | Whether it is a new test screen or a stored result screen | Do not use it as a current result |
| Smartphone app | When the selected result was recorded | Do not assume it is a new test |
| Shared screen photo | Whether the day you opened the photo matches when the result was created | Confirm the test time separately |
| Shared family records | Who produced the result | Do not mix it with your own result when deciding |
Decision order in a hypothetical situation
Suppose, for example, that a person getting ready for work sees a reading on the device screen and later realizes it was a screen reopening the result they had checked the night before. The facts to observe are that there was a number on the screen and that it is unclear whether that number was produced by a new test. If you interpret this as "I turned it on, so it must be today's result," you confuse viewing a record with a new test.
In this case, a possible action is not to use that screen as a current reading, and to decide whether a new test is needed following the procedure in the product manual. At the same time, do not change backup travel plans already made, such as a designated driver service, public transport, or riding with someone else. The completion criterion is not a number that looks low, but a state in which you can tell whether the result shows your current state and when it was created. If that criterion is not met, the basis for a driving decision is not in place yet either.
Recording is about keeping context, not collecting numbers
To make use of test records, it is a good habit to note the necessary context briefly next to each result. For example, if you distinguish how you saw the result, such as "checked directly on the device," "viewed earlier record in the app," or "screen sent by family member," it becomes easier to trace the meaning of the number later. For records whose test time is unknown, leaving them as "time unconfirmed" rather than forcing in a date reduces misunderstanding.
Even if you suspect the time shown on the device or app differs from the actual time, do not rewrite past records to match your memory. Keep what the original screen showed separate from the reason you suspect a time difference, and check the product's guidance for setting the time or handling records. Fixing a time display problem and deciding whether you can drive based on the result are separate matters.
Criteria for keeping past records out of today's decision
Stored results are useful for looking back on drinking habits and making agreements with family. However, the fact that yesterday's result remains does not mean today's test is done, and it does not explain your state after sleeping either. A test reading is reference information for personal self-checks, so on days when you are not sure it is a new result, or when how you feel and your judgment disagree, it is better not to decide to drive based on a single number.
Family members or people who share a vehicle can set simple agreements such as "when sending a result, include who tested and when" and "do not present a screen with an unclear time as a current result." These agreements are not rules for using the record feature more. They are a dividing line that keeps past numbers from replacing today's judgment.
※ Self-check results from our products are provided as reference information only. Actual enforcement standards and testing methods may differ by agency and equipment, so self-check results may differ from enforcement results, and the company accepts no responsibility for enforcement results.
