Is a Breathalyzer Ever Inaccurate?

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Breathalyzers are commonly used by police officers when they check whether the driver was drinking alcohol and how much alcohol they have in their system. 

The breathalyzers used by police have to meet some standards to show the accuracy of the testing. You can also get a breathalyzer for yourself since they are available for personal use, as well.

A breathalyzer is a device that is used to check the concentration of alcohol in one’s blood. Usually, it is called BAC, and it uses the persons’ breath. The first breathalyzers or breath alcohol tests date back to the 1940s. The modern devices came later, in the mid-fifties. 

When you drink alcohol, it goes into your blood and your lungs. Just like carbon dioxide diffuses out of your blood, the same happens with alcohol. When you breathe out, you exhale the alcohol. 

The breathalyzer is used to show how much alcohol there is in your breath. Usually, the breath-to-blood alcohol ratio is 2100:1. This means there are 2100 milliliters of alcohol in your blood for one milliliter of alcohol in your breath. 

In the USA, it is illegal to drive with .08% of alcohol in your blood (or higher than that). In that case, you are driving under the influence. There is a margin error with breathalyzers that can go from 15% to 25%.

Drunk drivers are later asked for a blood sample test; talk to your DWI attorney before you take any step.

What affects breathalyzer accuracy? 

The breathalyzer does not measure the alcohol in your blood in a tangible way. 

One of the factors that can affect the accuracy of breathalyzers is body temperature. Some people have a higher body temperature, which makes the breathalyzer result much higher. There are different blood composition which can also show higher alcohol readings. 

Lower readings may occur when the test is done before the alcohol is entirely absorbed in the blood (usually, it takes about two hours).

Another thing that can affect the breathalyzer test is the electrical interference that comes from a smartphone or police radio devices. Also, some breathalyzers cannot tell the difference between alcohol and other chemical compounds in the breath. Methyl compounds are present in paint removers, vinegar, and in people with diabetes. 

Some factors that can cause higher readings can include vomit in the mouth, mouthwash, and breath fresheners. 

Breathalyses need to be calibrated periodically, and their batteries should be replaced in order to keep their accuracy. 

Their software is unique, just like any computer, and relies on the system. This means the software can have glitches.

Another factor can be human error. Breathalyzers are not complicated to use, but they do require the person to know how to use them.

Also, the breathalyzer test should be done several times to give a precise result. Breathalyzers that use fuel sensor technology provide the most accurate results in repeated testing.

Environmental factors can also affect the testing; if there are paint, varnish, and chemicals (plastics or adhesives) nearby, it can affect the breathalyzer test.

How can you show that a breathalyzer test was not accurate?

If your attorney can show that the officers did not use every applicable calibration procedure, the court can decide that the breathalyzer test results are not entirely accurate as evidence in your case. 

If you want to get the initial evidence as inaccurate, you can be subpoenaing the maintenance of the device as well as calibration documents. The attorney should be able to prove that the instrument was not suitably tuned to show accurate results. 

The prosecution will have to prove that the defendant was intoxicated, but they will have to use another evidence (poor performance on field sobriety test). The final decision will come from the judge, of course. 

When to talk to an attorney

Every driver will experience at least one breathalyzer test in their lifetime. It is entirely normal, and there is nothing you should be scared of. Even if you had alcohol before the testing, remain calm and don’t refuse to do it. 

In case you are arrested and charged with driving while intoxicated, then you need to call a DWI attorney. The attorney will explain everything you need to know (law and procedure) and can help you with your case.

Your attorney will start an investigation on your case and will prepare your defense.

If you are in a similar situation, call our office and let our DWI attorneys help you with your case.

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