One of the most confusing things for the potential purchaser in the wonderful world of Breathalyzers is establishing exactly what sort of level of accuracy these devices have.
There are numerous companies out there (some with far higher marketing budgets than accurate production cost interests) who would have you believe their £25 unit is state-of-the-art, with levels of accuracy that rival the Police grade units. When you consider that an ACTUAL police grade unit is at least £700, you would think that it would be clear that a device that cheap can give little more than a few beeps and a colourful light display. But let’s look at these accuracy claims.
As a rule, devices which cost upto about the £60 mark are generally quoted as having an accuracy level of about “+/-0.02%BAC at the drink drive limit” – all of which sounds very impressive. But put into perspective, what it ACTUALLY means is that if the drink limit reads as 80mg, the device can be accurate by plus or minus 20mg – therefore a variable accuracy rate of 25%. Thats a big stretch. And that’s at the drink drive limit. At a quarter of the drink drive limit – the limit that anyone who works in Air, Rail or Maritime industries has to comply to – the accuracy rate technically would be plus or minus 100%. Ouch.
ACTUAL police grade detectors (such as the Home Office Approved Draeger 6510 or the AlcoDigital 3000 which uses the same sensor) have an accuracy rate of plus or minus upto 2%. In otherwords, that equivalent 80mg readout would vary by UPTO plus or minus 1.6mg.
There’s good reason these devices cost more. That’s because they work.