Breath tester

A small fuel cell in this portable breath tester catalyzes the oxidation of ethanol by oxygen in the air. 

A small fuel cell in this portable breath tester catalyzes the oxidation of ethanol by oxygen in the air. The oxidation generates an electric current that is proportional to the concentration of ethanol in the sample. 

A confirmation test using an evidentiary breath tester (EBT) if the screening test indicated a BAG of 0.02 or more. 

As a matter of procedure tihe measurement of drivers BAG is most often not based on direct measurement of the blood content. Instead drivers are asked to blow into a portable breath tester and their lung air is analyzed. Because the breath alcohol concentration is proportional to the BAG by a factor of 2.2727 (Vanlaar, 2005), the breath alcohol content can be easily converted into blood alcohol concentration. For example, a breath alcohol concentration of 0.22 mg alcohol per liter of exhaled air is equivalent to 0.5 g/1 in the blood, or 0.05% BAG. 

One of the more weird adhesion tests is the Mattox bad breath test . In this test, a person breathes on the film to condense moisture. If the film has a high residual stress, the moisture accelerates fracture propagation. When the film fails it blisters or flakes. Obviously, the uninformed individual attributes the failure to the bad breath of the tester. This test has the advantage that it can be done immediately and without equipment. If the film cannot pass this test it will probably fail in the future. The condensing breath often contaminates the film surface for further use and the test could probably be improved to be non-destructive. 

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