The part with semiconductor sensor ...

Although ... promises a hundredth accuracy, but displays only tenth. As you wonder sometimes, because the values ​​over time does not seem to sink. But if you comply with the rules (no smoking beforehand, waiting time after the last extremely glass ...), gives a good summary value. Especially early in the morning, you can test the rest of alcohol well - so be careful, even though you feel sober ... With the devices that have an electrochemical sensor (fuel cell), can not be compared - so do not argue with the police ... ;)