Crucially, many of the devices on trial underestimate blood alcohol concentration blood alcohol concentration (BAC) readings, falsely indicating the user is under the 0.05 limit. In gauging the results, CHOICE looked at how far each device deviated from the evidential machine’s readings (see our testing method
The disposables are only designed to tell you if you’re under or over 0.05 and both tended to err on the side of caution. Redline recorded no underestimates but overestimated breath readings twice. Of the seven electronic devices, Alcohawk and SoberMate delivered readings closest to the readings registered by the evidential machine, scoring above-average accuracy levels. Both also provided the least number of underestimates.
Overall, the worst performers were the FiT, Digitech and Alcolimit. All three scored poorly for accuracy, with an unacceptable number of underestimates (see the table, below).