Products: AlcoSense Pro breathalyser review

• Rating: ★★★★★
• RRP: £149.99
• Buy at: Halfords.com (£129.99 until January 31)

WHAT exactly is the point of a breathalyser? This is a question that may trouble many drivers, as most know the UK legal limit before getting behind the wheel… it’s roughly a pint or a glass or wine, right? Well, no, actually.

To get technical for a moment, in England, Wales and Northern Ireland you’re allowed 35µg (micrograms) of alcohol per 100ml of breath, 80mg per 100ml of blood or 107mg per 100ml of urine (except in Scotland, which has stricter rules).

This is massively confusing to laymen but unfortunately it’s impossible to simplify this into a safe number of drinks or units of alcohol after which you must not hit the road, because each drinker’s body breaks down alcohol at different rates. This is why official advice is not to drink at all before hitting the road, as there’s no way to be sure you’ll be under the legal limit.

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It’s good advice but does nothing to raise awareness of a rising problem: “morning after” drink driving.

If you have five or six drinks after work, for example at the office Christmas party, and are planning to drive to work the following day, you might think you’d be OK to get behind the wheel. However, it’s quite possible that your body won’t have cleared the alcohol out of your system by then.

Between 1995 and 2010 (when the latest data was compiled), the proportion of drink driving accidents that involve “morning after” drivers more than doubled from 7% to over 18%, while overall drink driving convictions has decreased.

Morning after checks is where a breathalyser can be really useful for law-abiding drivers; you might feel fine but it’s possible you’re still over the limit, which could end in disaster.

If you’re serious about making sure you won’t break legal limits, you’ll want a machine that can tell you how much alcohol is in your system as accurately as possible.

“If you plan to drink at the office Christmas party, it’s possible your body won’t have cleared the alcohol out of your system by the time you drive to work the next day”

Manufacturer AlcoSense claims its new Pro breathalyser is the most advanced on the market for its price point (£129.99 before January 31, then £149.99). It uses a 121mm² professional fuel cell sensor to detect alcohol in your breath, which is the same technology as used in police roadside breathalysers.

Its claimed ±0.05‰ BAC (Blood Alcohol Content) accuracy makes the AlcoSense Pro’s results similar to that of a police roadside breathalyser and around twice as accurate as most other products currently on the market at a similar price point.

To prove the Pro’s credentials, AlcoSense’s managing director visited the Driving office to demonstrate. The test was complex but involved using a machine to pump vapour from a solution of alcohol and water (using a human test subject introduces inaccuracies) into a Draeger police evidential breathalyser, which is used at police stations (they offer an industry-best ±0.03‰ BAC), and immediately after running the same test with the Pro.

The results: 

• Draeger Alcotest 9510: 0.312mg/l
• AlcoSense Pro: 0.32mg/l

The AlcoSense Pro got impressively close to the benchmark police evidential breathalyser. There’s a slight twist in that we used the Pro on Test Mode, which shows the exact reading; customers see an adjusted level that errs on the side of caution, adding a few mg/l and giving a final reading of 0.35mg/l. Both can be seen in the image below.

In addition, helpful features of the Pro include colour-coded results (red being over the limit), a backlit tube connector, the amusingly-named BlowCoach (shows in realtime whether you’re blowing too soft or hard to get an accurate reading), and a handy Time Until Sober reading.

The Pro also works abroad as it includes a database of legal limits in various countries/regions — you simply tell it where you are and it’ll do the rest.

There are some catches: AlcoSense recommends using a new blow tube or mouthpiece for each reading — blow tubes are £4.99 for a pack of 20 and mouth pieces (with a one-way valve) are £9.99 for 25 (there are five in the box to get you started) — and the sensor requires factory recalibration after 11 months, which costs £24.99 and will take two days to complete.

However, on the basis of our demonstration, the AlcoSense Pro appears to be a good investment for any law-abiding driver, especially during the Christmas party season, to make sure you’re not caught out the morning after. The alternative could ruin your life.