1. Insert a mouthpiece into the mouthpiece inlet.
2. Push the ON/OFF power switch that is located on the right side under the display window.
- The unit will show "on" along with a welcome sound and will start to countdown (15 ~ 35 seconds). This warm-up process prepares the sensor for testing.
3. A beep sound and "bLo" display will signal to begin testing. Blow steadily into the mouthpiece until you would hear the beep sound again.
- If you don’t blow within 20 seconds, the unit will automatically power off.
4. The unit will process the breath sample and display the test result.
- If the test result is over 0.050%BAC (default setting), "WARN" signal (Red LED) will light up along with "Alarm" sound.
- If you push the power switch when the Green or Red LED is off, the unit goes back to countdown stage for another test.