Breathalyzer Test FAQ

If the police pull you over on suspicion of driving under the influence, the officer may ask you to consent to a breathalyzer test. This test will read your blood alcohol content (BAC). These tests can pick up a trace concentration of alcohol and determine the level of alcohol in your body.

The police officer will use the test results and other evidence to determine whether you are over the legal limit. The prosecutor can still charge you with driving under the influence (DUI) even with alcohol testing results below the limit.

There is a lot of confusion about breath alcohol tests and DUI charges. These are some frequently asked questions (FAQs) about breathalyzer tests. However, states have different DWI and DUI laws. For more information about your DUI defense options, talk to a local DUI lawyer.

What Methods Do Officers Use To Determine Your BAC?

There are several methods that a police officer can use to determine your blood alcohol concentration (BAC). These methods include:

• Field Breathalyzer Tests: These tests measure the amount of alcohol in your breath and convert that number into an estimate of your BAC. This type of test happens during traffic stops. In many states, a field breathalyzer test is not mandatory. However, after a DUI arrest, you must submit to a breath or blood test at the police station.
• Field Sobriety Tests: These tests can indicate impairment by alcohol or other drugs. However, these are not accurate for measuring BAC levels. There may also be other reasons you can fail these tests, including medical conditions or uneven road surfaces. These are not mandatory.
• Chemical Breath Tests: These are mandatory after a drunk driving arrest. Under implied consent laws, drivers consent to submit to chemical tests if police have probable cause the driver is impaired. Chemical testing for alcohol usually requires a breath test done at the police station.
• Blood Tests: These can happen at a police station, jail, or hospital after an arrest on suspicion of DUI. Blood tests directly measure how much alcohol is in your system. These tests can also show the presence of drugs. However, the U.S. Supreme Court has ruled that police must obtain a warrant before forcing a blood test.
• Urine Tests: Such tests can occur at a police station or jail. They are uncommon for alcohol testing. However, the police may use them for drug DUI tests.

These tests all comprehensively examine your body’s current alcohol level. Things like alcohol vapor or residual mouth alcohol will only show on a breath test, and they can cause a false positive.

Alcohol consumption over a period of time will show on a blood or urine test. These tests can typically detect alcohol 24-48 hours after alcohol consumption.

Just How Does a Breath Test Work?

A breathalyzer, or any breath alcohol tester, involves blowing into a mouthpiece. A machine analyzes the volume of air that passes through the tube. Fuel cells test for the presence of ethanol in the breath. The breathalyzer test results are translated into a percentage of alcohol in the blood.

There are different types of breath testing equipment. Roadside breathalyzers are handheld devices used during traffic stops. These are not as accurate as more sophisticated breath test machines. They can give the law enforcement officer the evidence they need to make an arrest. However, these results are not admissible at trial.

The breath test devices at the police station are more accurate. However, they can also suffer from false positives. These machines need regular calibration and maintenance, or they could give inaccurate results.

How Accurate Are Breath Tests?

Breath test accuracy depends on several factors. Some types of breath testing devices can be more accurate than others. Police departments also have to regularly calibrate the machines to ensure their accuracy. Improperly maintained machines can also be inaccurate.

To be accurate, police have to administer a breath test properly. There are specific procedures for testing drivers. This includes blowing enough lung air to provide a test sample and monitoring the driver before and after.

Courts do not consider handheld breathalyzer tests accurate enough to be used in a criminal case. However, chemical testing machines at the police station are more precise. Prosecutors can use these breath test results as evidence that you were over the limit in a DUI case.

Is it Possible To Challenge Breath Test Results in Court?

There are many ways to challenge the results of a breath test in court. You can challenge the accuracy of the breath tests. A breath test could be defective. The police department may not have calibrated the machine as required by the manufacturer. If the police don’t correctly administer the tests or clean the machines, your breath test could be contaminated.

It may also be possible to challenge the test results because they were not conducted according to state law. For example, Pennsylvania law requires that an officer conduct two tests 10 seconds apart. Other states require a waiting period before and after administering the test.

Are Smaller Consumer Models of Breathalyzers Accurate?

In general, portable units manufactured and sold for personal use are helpful but not as accurate as those used by police departments. They can give you an idea of your BAC. However, don’t rely on these as a defense after a drunk driving arrest.

Several factors affect a driver’s BAC. Age, weight, gender, and using other drugs can affect your impairment after drinking. One person can go over the limit after one drink, but another may take three drinks to be legally impaired. Portable devices might be a good indicator of alcohol before you drive home, but there are risks involved.

If your consumer breathalyzer shows you are over the limit, you shouldn’t drive. Don’t take the chance if the breathalyzer shows you are under the limit but close. It only takes a few drinks for most people to be over the legal limit.

Should I Get Help From a DUI Attorney?

If you are facing charges of driving under the influence, you should consider talking to an attorney. A conviction could mean a driver’s license suspension, loss of driving privileges, jail time, fines, and higher insurance rates. A DUI defense attorney can help you avoid the most severe penalties.

A DUI lawyer can review your case and identify your legal defense strategies. Your attorney can negotiate to reduce the charges or go through a diversion program. Your DUI attorney can also represent you in court to fight the charges. Contact a DUI defense attorney for legal advice about your case.