Test Step Step 1 Attach mouthpiece, 2 AAA batteries (not included). Step 2 Press and hold the "power button" for 2 seconds, beep sound, the product starts. The screen shows a 15 seconds countdown, and the sensor is preheating. (Sometimes, the product may need to preheat multiple times, it will automatically reset and restart the countdown 1-3 times). Step 3 After successful preheating, a beep will sound and the screen will display a 10-second blow countdown. Blow for 3-5 seconds. (If alcohol is detected, the countdown will change to 5 seconds). Step 4 When blowing is complete, the sensor analyzes the exhaled gas sample and displays the result and an audible alert. (If no operation is performed, it will automatically turn off after 15 seconds of displaying the test results). Tips The measurement range of the breathalyzer is 0~0.199%BAC. If the measurement result reaches 0.199%BAC, even if you drink more, the measurement result will not riseIf you test multiple times in a row, it is recommended that each test be separated by more than 10 minutes. If the gas in the product is not completely volatilized, the result will be high ! Do not blow smoke, food or liquids into the breathalyzer; this can damage the sensor ! Do not test in areas with strong wind, smoke or heavy drinking ! If the display "LO" blinks after power on, it means the battery is low, please replace the battery in time to avoid affecting the test result ! If the device has been used five times in a row, please pause for two minutes before using it again to maintain the accuracy ! Please measure 20 minutes after eating, otherwise it will affect the accuracy of the results ! There is no essential difference in the accuracy of alcohol testers in detecting different types of alcohol. Its reliability depends more on the operating specifications and the physiological state of the person being tested Tips The measurement range of the breathalyzer is 0~0.199%BAC. If the measurement result reaches 0.199%BAC, even if you drink more, the measurement result will not riseIf you test multiple times in a row, it is recommended that each test be separated by more than 10 minutes. If the gas in the product is not completely volatilized, the result will be high ! Do not blow smoke, food or liquids into the breathalyzer; this can damage the sensor ! Do not test in areas with strong wind, smoke or heavy drinking ! If the display "LO" blinks after power on, it means the battery is low, please replace the battery in time to avoid affecting the test result ! If the device has been used five times in a row, please pause for two minutes before using it again to maintain the accuracy ! Please measure 20 minutes after eating, otherwise it will affect the accuracy of the results ! There is no essential difference in the accuracy of alcohol testers in detecting different types of alcohol. Its reliability depends more on the operating specifications and the physiological state of the person being tested