Working Principle of Alcohol Tester
The alcohol tests currently used by police basically use the same principle, that is, there is a proportional relationship between the alcohol concentration in the breath and the blood alcohol
concentration. When a person drinks, the alcohol is absorbed, but not digested, and part of the alcohol volatilizes, passes through the alveoli, and is exhaled again by the person. It has been
determined that the ratio of the alcohol concentration in the breath to the blood alcohol concentration is 2100:1, that is to say, the alcohol contained in every 2100ml of breath and the
alcohol contained in 1ml of blood are equal in quantity. . Through this ratio, the traffic police can quickly calculate the blood alcohol content of the subject by measuring the driver’s breath.
Without the “help” of the alcohol tester, the police can only determine whether the driver has drunk through a blood test or a urine test, but this inspection will take 1-2 days.
Theee Main Types of Alcohol Tester
Although the principles of the test are the same, different types of testers have completely different methods for how to quantify the amount of alcohol in the breath. At present, the
commonly used alcohol testers on the market can be roughly divided into three categories according to different testing methods. Breathalyzer is a tester that uses chemical reagents to
measure the alcohol concentration in exhaled breath. In 1954, a police officer in Indiana, Robert Berkenstein, invented the Breathalyzer, which became the world’s first alcohol test tool.
To this day, it remains the most frequently used alcohol tester in the world.
In addition to the components that a normal tester has, the Breathalyzer also comes with two glass bottles containing chemical mixtures. When the subject’s breath passes through these
glass bottles, if the gas contains alcohol, the mixture in the bottle will change from orange to green, and the resistance generated by the chemical reaction will also cause the needle to move,
accurately marking the alcohol in the breath. The concentration of blood alcohol is converted into blood alcohol concentration by the microcomputer.
The other two testers are the Intoxilyzer and the Alcosensor III or IV. The former determines the alcohol content by the degree to which alcohol molecules absorb infrared light; the latter
uses a fuel cell with positive and negative electrodes to complete the test. The electrodes are made of platinum metal, and when alcohol-laden gas enters the fuel cell, it reacts with the
platinum, producing an electrical current that generates a reading..
