There is no way to defeat the Breathalyzer 900/900A, the Intoxilyzer 5000, the Intoximeter, or any other breath testing device for several reasons:
First, as a part of the operating procedures, the police officer who is operating the machine is required to check your mouth for foreign objects. If he finds something in your mouth, he will require you to spit it out. A refusal to do so on your part is a violation of the Implied Consent Ruling and is a separate criminal offense in and of itself. (The Implied Consent Ruling states that by simply operating a motor vehicle on the roadways of your state, you have agreed that you will give a sample of your blood/breath/urine for the purpose of chemical analysis when asked to do so by a police officer. A refusal is a separate offense not related to the DUI offense. The ruling does not state that you have to be licensed in your state or licensed at all; you simply have to be "operating" a motor vehicle. It also does not differentiate between public and private roadways; it simply says "on the roadways." That's why the BS about pulling into a parking lot won't help you.)
Second, as a part of the operating procedures, the police officer is required to observe you for a minimum of 20 minutes before giving you the test. This is to give any residual alcohol in your mouth a chance to evaporate so the test doesn't read high, and to ensure that you haven't put anything in your mouth after he checked the first time. (Most alchohol evaporates within 15 minutes, but the extra 5 minutes is tacked on as a precaution.)
Third, when the officer is ready to take the breath sample from you he will instruct you to blow long and constant (or until he tells you to stop), not hard; the reason for this is that the breath sample the machine uses needs to be from the very bottom portion of your lungs. This sample is known as "deep lung" breath. This is the part of the lungs where the alcohol concentration is the same as the concentration in your blood. If the breath sample is taken from the top portion of your lungs, the reading will be TOO HIGH, and you don't want that.
If you "short puff" on the officer, you've violated the Implied Consent Ruling and you're screwed. The officer is also trained to recognize this; besides, if the officer has gotten this far in his DUI processing, he's got enough visual observation evidence to convict you already. The Breathalyzer test is just the icing on the cake. Also, if you do manage to hide something in your mouth from the officer and you produce it after he's done the test, you can grin all you want but all the officer needs to do now is process you for Violation of the Implied Consent Ruling. That little stunt is on YOU, not him.
Lastly, before the breath sample is taken from you the officer will calibrate the machine and ensure that it is operating properly. He does this by running an air sample from a "simulator" (a jar filled with a water/alcohol mixture that has a content equal to a BAC of .10%) through the machine. If the machine reads 0.10% BAC, it's operating properly.
The bottom line is - you can't beat the machine, so don't drink and drive.
Certified by the Commonwealth of Virginia as a Breath Alcohol Instructor for the Breathalyzer 900/900A and Intoxilyzer 5000.
Certified by the Commonwealth of Virginia as a Standardized Field Sobriety Test/Horizontal Gaze Nystagmus Instructor.
Trust me, I know what I'm talking about.