1. Insert the batteries (or charge the device depending on your model).
2. Attach a mouthpiece to the device if applicable.
3. Press the power or start button on your device and the countdown will begin.
4. When the countdown approaches 2, begin to inhale a deep breath.
5. When the countdown reaches zero, the BACtrack will beep and you will blow through the mouthpiece continuously and steadily for 5-6 seconds until the beep sound comes on and then stops.
6. Once the sensor has analyzed the breath sample, the estimated BAC value is displayed.
Please follow the link below for specific device information.