Breathalyser keeps reading 0 or provide different readings even after alcohol?

Semi-conductor and fuel cell breathalyzers are accurate at reading the amount of alcohol in a given breath sample. There are many factors however that affect the amount of alcohol in your breath and your reading.

  • Alcohol in your mouth - Alcohol in your mouth will dramatically increase the reading a breathalyzer gives, for this reason we always advise waiting 15-30 minutes from your last drink and rinsing your mouth with water before taking a test.  Some medicines and mouth washes have alcohol that can be detected by your breathalyzer.  Additionally semi-conductor breathalyzers may detect the presence of certain sugar alcohols which may cause higher than expected readings.
  • Alcohol or moisture in the mouthpiece - It is always recommended to use a new or clean mouth piece for each test.  Residual alcohol or moisture in the mouthpiece from previous tests can effect the readings from subsequent tests.
  • Moisture in the sensor - Excessive moisture in the sensor can effect the reading produced in the short term and in extreme cases can damage the sensor.  Moisture can get into the sensor inadvertently by accidentally spitting into the unit while you blow, typically semi-conductor units are more susceptible to this issue.  Always ensure your mouth is clean and free from excess saliva before you blow.  Excessive use in a short period can also cause moisture to build up inside the sensor, fuel cell sensors are better designed to handle multiple tests.  Industrial units with larger fuel cells are generally able to handle many tests without suffering a loss of accuracy.
  • Body type, Metabolism and Gender - The way each persons body reacts to and processes alcohol is different.  Your body type, metabolism, and gender can effect how quickly your body absorbs and burns alcohol.  Two people drinking the same drinks at the same time can have greatly different blood and breath alcohol levels.

Always remember that after heavy, rapid drink consumption, your blood and breath alcohol levels can continue to rise for an hour or longer after your last drink.