Almost every listing promises accuracy, yet only a few makers put a number on it. This page ranks breathalyzers by the tolerance their manufacturers actually publish, explains what such a figure promises and what it leaves out, and shows which models keep that accuracy over time through a clear calibration route. Everything here is based on the manufacturer's published specifications and public documentation, never on our own lab work.
BACtrack S80, a Pro Grade fuel cell with a stated tolerance at the higher 0.100% reference point and a yearly send-in calibration route.
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BACtrack Trace Pro, which pairs a published tolerance at 0.050% with a small body and Pro Grade parts.
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BACtrack Mobile, a pumped fuel cell unit whose tolerance is stated at 0.050% and whose readings are logged in the app.
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AlcoMate Revo, because a fresh precalibrated sensor module every 1,000 tests or each year keeps its stated tolerance current.
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Lifeloc FC10 publishes a tolerance across its whole range and appears on the NHTSA evidential list, and we cover it on the professional breathalyzer page without a shopping link.
Only tolerances that makers state are shown.
| Model | Sensor | Stated accuracy | Calibration | Best for |
|---|---|---|---|---|
| BACtrack S80 | Fuel cell, Pro Grade | +/- 0.005 at 0.100% BAC, at 25 C | Send-in service, maker suggests yearly | Precise personal readings |
| AlcoMate Revo | Fuel cell, replaceable module | +/- 0.005 at 0.10% BAC | User replaces module, 1,000 tests or yearly | Daily and shared testing |
| BACtrack Trace Pro | Fuel cell, Pro Grade | +/- 0.005 at 0.050% BAC | Send-in service, maker suggests yearly | Pocket carry |
| BACtrack Mobile | Fuel cell with breath pump | +/- 0.005 at 0.050% BAC | Send-in service, every 6 to 12 months | App logging |
| BACtrack C8 | Fuel cell | Not published by the maker | Send-in service, interval not published | Phone pairing |
| BACtrack C6 | Fuel cell | Not published by the maker | Send-in service, interval not published | Keychain carry |
| BACtrack Go | Semiconductor | Not published by the maker | Send-in service, every 6 to 12 months | Rough budget checks |
Figures are the maker's published specifications.
A line such as "+/- 0.005 at 0.050% BAC" means that when the maker fed the device a reference gas at that level, the reading stayed within half a hundredth of a percentage point. It is a promise about one point on the scale under controlled conditions, usually a set temperature.
Two consequences follow. First, a tolerance quoted at 0.100% and one quoted at 0.050% are not identical claims, since the error a sensor shows can change across its range. That is why the S80 and the Revo lead this table on a narrow margin rather than a clear win over the Trace Pro and Mobile. Second, the figure describes a freshly calibrated unit. A sensor that has gone a year past its service date can sit well outside it while the display still looks confident.
A maker that publishes the full curve, as Lifeloc does for the FC10 (+/- .005 up to .100 and +/- 5% from .100 to .400), gives buyers the most complete picture. Consumer makers rarely go that far.
Our guide on how accurate are breathalyzers walks through the other factors that move a reading.
The S80 is the consumer model with the most detailed accuracy statement in BACtrack's range.
Who it suits: buyers who want the most documented consumer handheld and are happy with a standalone unit.
What to know: no app, no test memory, and the maker gives two different sets of dimensions. Details in the BACtrack S80 review.
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The Revo states the same tolerance at 0.10% as the S80, and its maintenance model is built around keeping that figure true. Instead of a send-in visit, the owner fits a new factory calibrated PRISM module.
Who it suits: workplaces, treatment programs and busy households where accuracy has to hold through hundreds of blows.
What to know: professional price band plus the ongoing module cost; check your unit's serial number because module types differ by purchase date. The maker's DOT approval claim could not be matched to an NHTSA list entry. See the AlcoMate Revo review.
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Who it suits: people who want a documented tolerance in something that fits a pocket.
What to know: the tolerance is quoted at 0.050 rather than 0.100, display resolution is not published, and maker pages disagree on the battery size. Read the BACtrack Trace professional breathalyzer review.
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A built in pump draws a consistent volume of breath across the sensor, which removes some of the variation that comes from how hard each person blows.
Who it suits: readers who want accuracy plus a running history in the app.
What to know: there is no screen on the device, the rechargeable battery is not replaceable, and the sensor needs a blow at least monthly to stay in condition. Full notes in the BACtrack Mobile Pro review.
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The BACtrack C8 and C6 use a fuel cell, which is a good sign, but BACtrack describes their accuracy only in words such as "professional-grade accuracy". The BACtrack Go uses a semiconductor sensor and also has no numeric tolerance. These can still be reasonable buys for their use, and they appear in our best breathalyzer ranking, but they cannot rank in a list built on stated accuracy. The Draeger Alcotest 5820 is a professional instrument listed by NHTSA as evidential, yet it carries no numeric accuracy on its product sheet, is marked for law enforcement purposes only in the US and is shown as end of sales; our draeger breathalyzer review covers it for reference.
A precise sensor only delivers precise numbers when it is used correctly and kept in calibration.
Fuel cell sensors win on accuracy for a reason: they react to alcohol specifically and drift slowly. Semiconductor sensors cost less but can respond to other compounds and lose accuracy faster. The fuel cell vs semiconductor breathalyzer page explains the difference, and the fuel cell breathalyzer category lists every fuel cell model we cover.
Among models with a published figure, the BACtrack S80 and AlcoMate Revo state +/- 0.005 at the 0.10% reference, with the Trace Pro and Mobile stating the same tolerance at 0.050%.
Evidential instruments are built and maintained to a formal standard and checked under a set procedure, so they are held to stricter rules than a personal screening device.
Timing, mouth alcohol, blowing technique, temperature and calibration status each shift a result, so small differences between devices are normal.
You can use it as a rough guide, but without a stated figure there is nothing to hold the maker to, so do not lean on it for important decisions.
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