http://www.myearnathomeclub.com/safe-driving-breathalyzer/

Safe Driving Breathalyzer The S80 Pro provided an identical reading. Testing again 40 minutes after I’d stopped drinking, the police’s hardware registered the same 0.09 percent BAC level as it had before, while the S80 Pro provided a reading of 0.089 percent. Not spot-on, but very close. Of the 15 breathalyzers we’ve used in three separate tests, the S80 Pro is the only one to prove nearly as accurate as the police hardware.

Testing yourself or a friend with the S80 Pro is easy. Insert a new mouthpiece, press the Start button, and in less than 20 seconds you’re ready to begin. The display first shows how many tests the hardware has performed (which helps you know when to calibrate it, usually after about 1,000 tests).

Then it shows a 12-second countdown, after which you inhale deeply and then exhale into the mouthpiece. The device requires five seconds of your steady exhaling to collect enough air to take a reading. When the S80 Pro has enough air, it beeps, telling you to stop blowing. Three seconds later, your test results pop up on the large backlit display—which is easy to read in a dimly lit bar even if your vision is somewhat compromised.

http://www.myearnathomeclub.com/safe-driving-breathalyzer/