Alcohol detector Features Sophisticated, highly-selective semiconductor sensor providing highly reliable accuracy 3 digits digital LCD display(0xx%bac) Wide detection range:0.01~0.40%bac Long-term stability Short warm-up, response and recovery time Audible alarm alerting user to positive test Operation Turn the switch on(pressit down). The buzzer sounds once. The detector will start the countdown from 20 to 00 on the screen and finally display 0.00, indicating the sensor and circuit ready for test. In this stage, if you don\'\'t blow to the breath pole within 70 seconds, the screen will automatically display off and the buzzer will sound discontinuously for turn-off. Blow alcohol to the breath pole and test the level of your bac. The screen displays the level of bac. If the level on the screen is more than 0.05, the buzzer sounds alarm quickly. Otherwise, only the level is displayed on the screen. The screen will display off and the buzzer sounds discontinuously for turn-off after the test lasts for seventy seconds. Note: If the tester has no response to the gas, you are kindly requested to take step 1 for two or three times repeatedly, for the tester needs a certain time for warming up. For the successive test, take the above steps again. The screen displaying ee indicates the sensor in error. The screen keeping flickering indicates low voltage. Specifications Sensor: Highly sensitive semiconductor alcohol sensor Powered by two 1.5v batteries Battery usage limit: Continuous use for 50 times Test level:0.01%bac~0.40%bac Warm-up time: Less than 20s Response time: Less than 5s Dimension:105*20*40(mm)precautions For accurate result, do not smoke or eat anything for 20 minutes prior to testing yourself. After drinking, it is recommended to test after 20 min. It is because it takes 20 minutes approximately for alcohol to be absorbed into blood from the digestive organs, and residual alcohol remaining in the mouth takes this long to dissipate. Avoid testing under strong wind or in the closed room with contaminated air. Recharge the battery or replace it when the low voltage comes on. Avoid blowing liquid into breath pipe.