In households where a personal breathalyzer is shared with parents, the wording of a short guide matters as much as how to use the device. Family members may give someone the go-ahead to drive after seeing a number on a small screen, or someone who gets stuck operating it may test again and again looking for an answer. A breathalyzer is a self-test device that displays alcohol-related values based on breath, and the displayed value is not a permit that settles whether you can drive.
The purpose of a short guide is not to cut the usage procedure down however you like. It is to help people find the official user manual for that model and to steer them toward leaving the car behind when they are unsure of the result or not feeling well. Some products, such as the DATECH AF-40BT, support both standalone use and smartphone app pairing, but it is safer not to add to the card any screen indications or button sequences that have not been confirmed by official information.
The first sentence sets the role of the number
The first line of the guide should state what the device is for. For example, writing "a self-test for reference before driving" reduces the chance that family members turn the number on the screen into a verdict on whether someone can drive. Right after that, put the action principle: "If the result is uncertain or you are not feeling well, do not drive; choose another way to travel."
Do not include sentences that link a specific value to driving. Display units can differ by device, and even the same number can be badly misunderstood if family members interpret it without context. %BAC is a notation for blood alcohol concentration as a percentage, ‰ is a per-mille notation, and mg/L is a notation for breath alcohol concentration. Rather than explaining the meaning of the values at length, it is better for the card to say: "Check the display unit, and do not decide whether to drive from the number alone."
Write confirmed information and where to find things on the card
A one-page card does not replace the detailed manual. Include information people need to find right away, such as the model name, where the manual is kept, whom to contact for help, and how to travel when not using the car. If you are sharing an AF-40BT, state that product name clearly and do not let the operating steps of another breathalyzer get mixed in.
| Card section | Short sentence to write on the card | Why this is needed |
|---|---|---|
| Device identification | "This guide is for the AF-40BT." | It will not get mixed up with guidance for a similar-looking device. |
| Manual | "The user manual is kept in ___." | People can find the official procedure without relying on memory. |
| Reading the result | "Look at the display unit together with the current test result." | It reduces the mistake of reading the number on its own. |
| When it is hard to decide | "If unsure, leave the car and travel by ___." | Instead of repeating the test until the desired result appears, it switches to a travel plan. |
The official AF-40BT product information mentions standalone use and app pairing, storage of test results, and display ranges in %BAC, ‰, and mg/L. However, this information alone does not let you say which items appear on a particular screen or in what order to operate the device. Put such details on the card only when they have been confirmed in the user manual that actually came with the device.
Shorten sentences that cannot be read in one pass
What matters on a card shared with parents is not the number of characters but how quickly someone can find what to do. Rather than vague expressions such as "check that it's normal," write the object and the action, such as "find the manual" or "leave the car and call a taxi." For contacts, too, rather than writing just "family," agree on the name and the way to call that the person has consented to, so it can actually be used when needed.
If the text is small or the wording is unfamiliar, read the card aloud next to the device. The point here is not to test whether a family member can operate the device on someone's behalf, but to see whether the user can find where the manual is and an alternative way to travel. For information they could not find, rather than lengthening the sentences, change where things are kept or reorder the card to move it further up.
Review the guide with a hypothetical situation
For instance, suppose that on the morning after a company dinner, one of your parents takes out the shared breathalyzer but finds it hard to read the number and display unit on the screen with confidence. The fact to observe here is not whether the number looks high or low but that they do not clearly understand the current result. If they also could not immediately find the model name and manual location written on the card, that too is a problem the guide needs to solve.
Do not interpret this situation as "it looks low, so it's fine to drive." Possible actions are to check in the user manual how to read results for that model, or to ask the designated person where the manual is. If the decision is still unclear, switch to a travel method written down in advance, such as a taxi, public transportation, or riding with someone else. The completion criterion in this case is not getting a particular number but reaching a state where the person either understands the current result on their own or carries out a travel plan that does not involve driving.
Decide both convenience and visibility for app records
App pairing and on-device storage can be used to look back on testing habits, but on a shared device, results may get mixed up as to whose they are. The AF-40BT supports storing test results and pairing with a smartphone. However, that does not mean the whole family must see the stored records, and using the device on its own without the app is also an option.
If you decide to use the records, first agree on who can see their own records and who can see them only when asked for help. For example, you could suggest noting in a personal memo who took each test, but it is better to avoid sharing other family members' results without their agreement. Rather than putting a long privacy agreement on the card, write "Records are shared only within the agreed scope," and agree on the specific scope separately as a family.
End the card with travel options
After finishing the guide, check only whether four things can be found right away: the model name, where the manual is, the help contact, and an alternative way to travel. When you feel like adding more operating instructions, first check whether the official manual for that model has the same content. Maintenance matters, such as product condition checks or when calibration is due, are also better handled in separate guidance rather than on a short family card, to reduce confusion.
A good guide does not give family members the authority to judge a number. Instead, it makes visible the path back to the actual product guidance and the choice not to drive when unsure. Making it short does not mean leaving out necessary cautions; it means making the necessary actions easy to find without hesitation.
※ Self-test results from our products are provided as reference information only. Official enforcement standards and testing methods may vary by agency and equipment, so self-test results may differ from enforcement results, and the company accepts no liability for enforcement results.
