03.Test method / Voluntary standard
Ten trialists — six men and four women of varying ages and weights — took part in our trial. Each reading from the handheld breathalysers was compared with that of a calibrated Dräger Alcotest 7110, an evidential breathalyser used by police for the detection of drink-driving offences in all states except NSW and Queensland. The evidential machine readings were used as the benchmark to assess the accuracy of readings taken from our trial breathalysers.
After abstaining from alcohol for 24 hours, trialists took a reading on the evidential machine to confirm they registered zero BAC. They familiarised themselves with how each breathalyser worked and rated them for ease of use, which included understanding the instructions, preparing the breathalyser for use and reading the results.
After eating lunch, the trialists were allowed to consume between one and three standard drinks (see What’s in a Standard Drink) in one hour, followed by a 20-minute break to dispel mouth alcohol before using the breathalysers.
The trialists then used each breathalyser, including the evidential machine, and recorded their BAC readings. They were asked how confident they felt about driving a car safely and whether they believed they were under the legal limit.
Voluntary Australian standard
Of the devices on trial, the SoberMate, Andatech, Alcolimit and Redline are certified with the voluntary Australian Standard, AS 3547, which specifies a set of minimum performance standards for personal breath alcohol testing devices.
The standard’s test method is to pass vapour containing alcohol through the breathalysers. While the devices performed to Australian Standards, our trial indicates that certification does not reflect their performance in real-life scenarios.