1. After you take a drink of alcohol, the air in your mouth and esophagus is highly alcoholic, If you were to breathe into a breathalyzer right after drinking liquor, for example, your BAC estimate would be very high-and also very inaccurate. Waiting 20 minutes allows the air in your mouth and esophagus to return to a normal level, it is because 20 minutes is approximately for alcohol to be absorbed into blood from the digestive organs, and residual alcohol remaining in the mouth takes this long to dissipate.
2. For accurate result, do not repeat next testing within 3 minutes after last time.
3. Do not smoke and eat for 20 minutes prior testing.
4. Please do not use chemical or corrosive solution/liquid to wipe this product to prevent other liquids flow into the air-blowing tube.
5. Please do not be used normally in the environment with high concentration gas.
6. Do not use in the enclosed space with paints, pesticides, alcohol and other corrosive gas or dirty air.