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DUI Breath Testing in Knoxville, TN

You’ve been arrested for DUI? Now what?

Breath Testing for Blood Alcohol Concentration: The Basics

When a police officer suspects a driver of operating a vehicle under the influence of alcohol, one of the most common procedures is to administer a breath test for Blood Alcohol Concentration (BAC). This test, often done using a device commonly known as a breathalyzer, estimates the amount of alcohol in the bloodstream.

How does it work? The breathalyzer measures the amount of alcohol present in one’s breath and uses this to estimate the BAC. When you consume alcohol, it enters your bloodstream and is eventually exhaled through your lungs, which is why a breathalyzer can detect its presence.

Intoximeter EC/IR II

In Tennessee, the most common device used for evidential breath testing is the Intoximeter EC/IR II. the Intoximeter EC/IR II is a device used by law enforcement agencies to measure an individual’s blood alcohol content (BAC) through a breath sample. The device operates using two primary technologies: electrochemical fuel cell analysis and infrared spectroscopy. Let’s break down how each of these technologies work:

Electrochemical Fuel Cell Analysis

This part of the device is specifically designed to detect alcohol. When a person blows into the device, any alcohol in their breath will react with the chemicals in the fuel cell. This reaction generates an electric current. The greater the alcohol content in the breath sample, the greater the electrical current will be. The device then translates this current into an estimated BAC.

Infrared (IR) Spectroscopy

The infrared component of the device complements the fuel cell analysis by providing a secondary means of measuring alcohol content. After the breath sample is taken, it is subjected to an infrared light. Different molecules, including alcohol molecules, absorb infrared light at different frequencies. The device measures the absorption of this light, allowing it to identify and quantify the amount of alcohol in the sample. The device's name "EC/IR" stands for Electrochemical Cell/Infrared, referring to the two methods of detection used. The "II" simply denotes the second generation of the device.

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DUI Breath Testing Process

Here is a simplified step-by-step process of how the Intoximeter EC/IR II works:

  1. The individual breathes into the mouthpiece of the device.
  2. The breath sample is first analyzed by the electrochemical fuel cell, which generates an electrical current proportional to the alcohol content.
  3. The same breath sample is then subjected to an infrared light. The alcohol in the sample absorbs some of this light.
  4. The device measures how much light was absorbed to identify and quantify the alcohol content.
  5. The results from the fuel cell analysis and infrared spectroscopy are then combined to give a more accurate and reliable estimate of the individual’s BAC.

By using these two methods of detection, the EC/IR II can provide a highly accurate measure of an individual’s BAC. But like any machine, it’s not infallible. The device must be properly maintained, and the test must be correctly administered to ensure accurate results.

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Limitations of Breath Testing

While breath testing may seem straightforward, it’s crucial to understand its limitations. Many factors can affect the accuracy of a breathalyzer test, leading to potential false positives.

Breathalyzer devices must be properly calibrated and maintained for accurate readings. If not, the test results may be skewed. Like any machine, breath testing devices are not infallible.

Certain diets or medical conditions can produce substances in your body that a breathalyzer may interpret as alcohol. For instance, people with diabetes or those on low-carb diets may have elevated levels of acetone, which can be falsely detected as alcohol.

Exposure to certain substances, like some solvents or adhesives, can impact the test’s accuracy. Even alcohol present in mouthwash or medication can lead to a false positive when present to close to the time of testing.

The test must be administered correctly, adhering to the specific guidelines. If the officer doesn’t follow the correct procedure, the results may not be valid. Two Tennessee cases govern the steps and evidence necessary to admit a breath test result into evidence in court.

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Police officer with a breath testing device

How a DUI Defense Lawyer Can Help

If you’ve been arrested for a DUI and have given a breath test, it’s essential to consult with an experienced DUI defense lawyer. They can provide invaluable assistance in several ways:

Understanding the Charge: A DUI charge can have severe consequences, including fines, loss of driving privileges, and potential jail time. Your lawyer can help you understand the charge, the potential penalties, and the impact on your life.

Investigating the Arrest: Was there a valid reason for the traffic stop? Were your rights respected during the arrest? Your lawyer will analyze every detail of your case, looking for possible defenses.

Challenging the Breath Test: Your lawyer can investigate whether the breath test was conducted correctly and if the breathalyzer device was maintained and calibrated properly. If there were errors in the testing procedure or machine maintenance, your lawyer could use this information to challenge the test’s reliability in court. Further, your lawyer must determine if the breath test is admissible under Tennessee’s case law.

Representing You in Court: If your case goes to trial, your lawyer will fight for your rights and work to present the best possible defense on your behalf.

Negotiating Plea Deals: If it is in your best interest, your lawyer can negotiate with the prosecutor to reduce the charges or penalties.

Call Barnes & Fersten for Help with Your DUI Case

When you’re facing a DUI charge, you need someone in your corner who understands the complexities of DUI law and breath testing science. Our DUI defense firm in Knoxville, TN, is backed by years of experience and a track record of success in defending clients in similar situations. We strive to protect your rights, challenge questionable BAC testing results, and work tirelessly to seek the best possible outcome for your case.

For a consultation or more information about our services, please don’t hesitate to get in touch.  Call us at (865) 805-5703 or fill out the contact form on this page. Remember, a DUI charge doesn’t have to define your future – we’re here to help guide you through this challenging time.

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