It’s important when taking a blood alcohol reading that you get air from the deepest part of your lungs. This is because the air that comes from the mouth and the esophagus is often laden with alcohol from drinking, and therefore contains a higher alcohol concentration than your blood. This is one of the reasons why users should wait 15-20 minutes after drinking to test themselves. When you get a deep lung air sample, you are getting an estimate of your actual BAC. For this reason, our pro grade units only take a sample at the very end of a five-second breath—and this is facilitated by the solenoid air pump.
The normal volume the average user breathes into a breathalyzer during a five second sample is about 5,000 mL. The first 3,500 mL is disregarded because it comes from the mouth and esophagus. It’s only in the last second or so of the sample that the air pump opens and pushes the final 1,500 mL across the sensor. This ensures the air is all coming from one direction, which is important for accuracy, and also only allows air from the deepest part of the lungs to be tested. This method will yield the most accurate BAC reading.
All of the professional grade BACtrack units use solenoid air pumps in order to achieve the most accurate readings possible.