A portable breathalyzer is a handheld you can take to a dinner, a wedding or a weekend away and use on the spot. Size alone does not make a good one. What matters is the sensor inside, how quickly it is ready, how long the batteries last, and whether it copes with the temperatures it will meet in a bag or a car. This page compares the handhelds whose makers publish those details and explains the trade-offs between pocket size and precision, based on the manufacturer's published specifications and public documentation.
BACtrack S80, a fuel cell handheld with a stated tolerance and around 1,500 tests per pair of AA batteries.
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BACtrack Trace Professional, about 3 oz and barely over half an inch thick, with a tolerance stated at 0.050% BAC.
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BACtrack Mobile, a fuel cell tester of roughly 2 oz that charges by USB and shows results in its app.
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AlcoMate Revo, a fuel cell handheld whose sensor module you replace yourself, so it does not go away for factory calibration.
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Four details decide whether a handheld travels well.
These handhelds are personal screening devices, not a substitute for a formal test.
This is an estimate. It cannot tell you whether you are safe or legal to drive. If you have been drinking, do not drive.
| Model | Sensor | Stated accuracy | Calibration | Best for |
|---|---|---|---|---|
| BACtrack S80 | Fuel cell (Xtend) | Plus or minus 0.005 at 0.100% BAC | Send-in service, at least yearly per maker guidance | Bag or glovebox, many tests |
| BACtrack Trace Professional | Fuel cell (Xtend) | Plus or minus 0.005 at 0.050% BAC | Send-in service, at least yearly per maker guidance | Jacket pocket |
| BACtrack Mobile | Fuel cell (Xtend) | Plus or minus 0.005 at 0.050% BAC | Send-in service, every 6 to 12 months per user guide | Phone users |
| BACtrack C8 | Fuel cell (BluFire) | Not published by the maker as a number | Send-in service, no model specific interval published | Small with own screen |
| AlcoMate Revo | Fuel cell, swappable module | Plus or minus 0.005 at 0.10% BAC | New module every 1,000 tests or yearly | Frequent travelers |
| Model | Size (maker figures) | Weight | Power |
|---|---|---|---|
| BACtrack S80 | 2.3 x 4.8 x 0.8 in or 2.0 x 4.75 x 0.75 in, per differing maker pages | 4.8 oz with batteries | 2 AA, about 1,500 tests |
| BACtrack Trace Professional | 4.25 x 1.875 x 0.625 in | About 3 oz | AA or AAA per differing maker pages, about 1,500 tests |
| BACtrack Mobile | 1.75 x 2.75 x 0.63 in | 1.7 to 2 oz per maker documents | Rechargeable, not replaceable |
| BACtrack C8 | 2.50 x 0.66 x 2.20 in | About 2 oz | 1 AAA, about 250 tests |
| AlcoMate Revo | 4.0 x 2.0 x 0.6 in | Listed by the maker as 1.0 oz | 2 AAA |
Who it suits: anyone who keeps the tester in a bag or car console and wants many tests before a battery change.
What to know: it is the heaviest model here, and like other send-in units it is away from you while it is being calibrated. See the bactrack s80 review.
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Who it suits: a person who wants fuel cell precision in something flat enough for an inside pocket.
What to know: maker pages disagree on whether it takes AA or AAA cells, so check the listing before buying spares. The bactrack trace professional breathalyzer review has the rest.
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Who it suits: a traveler who always has a phone and wants the lightest fuel cell option.
What to know: there is no screen on the unit and the battery is sealed, so a flat phone or a flat tester ends the session. Read the bactrack mobile pro review.
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Who it suits: someone who wants a small unit that works with or without the phone.
What to know: the AAA battery lasts about 250 tests, far fewer than the S80 or Trace. More in the bactrack c8 review.
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Who it suits: a frequent traveler or a field supervisor who cannot be without a tester for a couple of weeks.
What to know: it belongs to the professional price band, and the maker does not publish its warm-up or result time on the product page. See the alcomate revo review.
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Choose the sensor before the shape. A fuel cell handheld is worth the extra bulk over a semiconductor keychain if you plan to rely on the numbers. If a key ring really is the only place you will carry it, our keychain breathalyzer page covers the smallest options and their limits.
Think about where the tester will live. Many owners keep one in the car, but heat and cold are hard on sensors and batteries, so check the operating range in the manual and bring the unit inside in extreme weather. Our breathalyzer for car guide explains the difference between a personal tester and an ignition interlock.
Carry spare mouthpieces and fresh batteries, and note the calibration date. Waiting at least 15 minutes after the last drink or meal, or 20 minutes where the BACtrack manuals ask for it, protects both the result and the sensor.
You can carry it in the car, but avoid leaving it there in heat or frost, since makers list operating ranges such as 32 to 96.8 F for the BACtrack Mobile.
Size matters less than the sensor, and several compact fuel cell units carry the same stated tolerance as larger handhelds.
Replaceable AA or AAA cells are easier on the road, while a rechargeable unit needs a cable and regular charging.
It is a small battery powered device, so check your airline and current airport security rules before you pack it.
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