Alcohol breath tests – methods, factors and implications


When an individual is pulled over under the suspicion of driving while intoxicated, they are usually tested with the aim of determining whether they are in fact under the influence of alcohol and drugs. The majority of these breath tests are for the initial screenings, while more concrete results usually come in the form of urine or blood testing. On the most widely used testing methods is the alcohol breath test. This particular test requires an individual to blow into a small, handheld device, to provide a sample which will be analyzed for any traces of alcohol.

Breath analyzing technologies

22mbnbkBreath analyzing devices, such as Breathalysers or Intoximeters, commonly use technologies such as the fuel cell technology and infrared spectrometry, to accurately measure the levels of alcohol in one’s breath. The devices that utilize infrared spectrometry are usually used for evidential testing. On the other hand, fuel cell models are commonly used for preliminary testing on-site when an individual is stopped under the suspicion of driving under the influence of alcohol.

The mechanisms

While the exact mechanisms of these devices are perhaps too complicated to explain here, we will cover just the basics. Infrared spectrometry technology functions by measuring the exact wavelength of ethyl alcohol, which alcohol beverages contain. Fuel cell models work by turning the alcohol content into an electric current, which is then properly measured.

Not always 100% accurate

Since these breath testing devices are nothing more than just machines, they do not always produce 100% results. There are always chances of false readings occurring. A common issue with the majority of a breath analyzing devices is the fact that they do not only measure and identify the ethyl alcohol. Also, they are also known to identify other substances, as well, especially the ones that have a very similar molecular structure of ethyl alcohol.

Main factors

There are also some factors that can influence the functioning of a device and its readouts. Some of the well-known factors that could trigger a positive reading from a breathalyzer, even though an individual hasn’t had a single drink, can include the temperature of the surrounding air, that person’s diet, as well as various occupational substances. For example, a person, whose job involves being surrounded by substances, such as cleaning products or paint, can inadvertently end up inhaling them. This can cause the breathalyzer to produce positive results, despite the fact that the person hasn’t been drinking before the test. Also, individuals, who are diabetics or who are on various diets, are likely to have substantially higher acetone levels, which some breath analyzing devices can confuse with ethyl alcohol.

Human errors and false readouts

33nnnHowever, just because a person blows a breath test that ends up positive, does not mean that they will be automatically charged and convicted of Driving Under the Influence. More often than not, a simple error committed by the officer is more than enough for the charges to be dropped. Also, faulty breath testing equipment can easily malfunction and display improper readings.

In case there is a trial, a person can rely on the services of a professional DUI lawyer, who will take into account these factors, as well as any other factors. With these, a lawyer will build a strong defense against any DUI allegation.

Angela Begay