Originally Posted by Oddjobdth
About the breathalyzer use a timer and wait atleast 10 minutes from your last drink of any alcohol.
The instructions for mine say 20, and I always make sure to check the clock. Using it without waiting can screw up the sensor.
That does make it challenging to have a "how drunk are you" party, but it can still be fun.
I've been using this one, I like the replaceable sensors, because with other models I've had in the past, by the time I need it calibrated, it's so old I can't find anyone to calibrate it.