Breathalyzer tests are one of the most common tools used by law enforcement officers to determine a driver’s level of intoxication during a DUI investigation. These devices measure the alcohol content in a person’s breath and provide an estimate of their blood alcohol concentration (BAC). While breathalyzers are widely used, questions about their accuracy and reliability have persisted for years. This article examines the role of breathalyzers in Florida DUI cases, investigates common issues with calibration and reliability, and discusses how test results can be challenged.

How Breathalyzers Work in DUI Cases

Breathalyzers work by measuring the concentration of alcohol in the driver’s breath and using that data to estimate their BAC. When a person consumes alcohol, it enters their bloodstream and is eventually expelled through the lungs when they exhale. A breathalyzer captures a sample of the exhaled breath and measures the amount of alcohol vapor present.

The device calculates the BAC based on the ratio of alcohol in the breath to the alcohol in the bloodstream, which is typically 1:2100. This means that breathalyzers assume there is one part alcohol in the breath for every 2,100 parts of alcohol in the blood. If the measured BAC exceeds Florida's legal limit of 0.08%, the driver is presumed to be impaired and may be arrested for DUI.

Investigating the Reliability of Breathalyzers

Although breathalyzers are commonly used in DUI cases, their accuracy is often questioned. Several factors can impact the reliability of breathalyzer results, leading to inaccurate BAC readings.

Factors That Can Affect Breathalyzer Accuracy

  1. Calibration Issues: One of the most common issues with breathalyzer tests is improper calibration. Breathalyzer devices must be regularly calibrated to ensure accurate readings. Calibration involves adjusting the device’s internal sensors to measure alcohol concentrations correctly. If the device is not properly calibrated or has gone too long between calibrations, it may produce inaccurate results.

  2. Environmental Factors: Breathalyzer readings can be influenced by environmental conditions such as temperature, humidity, and altitude. These factors can affect the way alcohol evaporates from the bloodstream and the readings obtained by the breathalyzer.

  3. Mouth Alcohol: Alcohol that remains in the mouth, throat, or esophagus can result in artificially high BAC readings. This residual alcohol may come from recent drinking, mouthwash, or even belching. A breathalyzer is supposed to measure deep lung air, not mouth alcohol, but it cannot always distinguish between the two, leading to inflated results.

  4. Medical Conditions: Certain medical conditions, such as acid reflux, diabetes, or respiratory issues, can affect breathalyzer results. For example, individuals with diabetes may have elevated levels of acetone in their breath, which can be mistaken for alcohol by the breathalyzer.

  5. Improper Testing Procedures: The accuracy of breathalyzer results also depends on the officer following proper testing procedures. If the test is administered too soon after drinking or if the officer fails to follow protocol, the results may be inaccurate. This includes waiting for the required observation period, ensuring the driver has not burped or regurgitated, and using the correct techniques to obtain a breath sample.

Common Issues with Breathalyzer Calibration

Breathalyzer devices must be properly maintained and calibrated to ensure accurate readings. Calibration is the process of fine-tuning the sensors within the breathalyzer to measure alcohol accurately. Without regular calibration, the accuracy of the device may diminish over time, leading to false readings.

Importance of Calibration

Calibration involves adjusting the breathalyzer’s internal settings to match known alcohol concentrations. This ensures that the device provides accurate readings during a DUI investigation. Florida law requires that breathalyzers be calibrated at regular intervals by certified technicians. However, in some cases, calibration is overlooked or improperly performed, which can result in erroneous BAC readings.

Effects of Miscalibration

When a breathalyzer is not properly calibrated, it may either overestimate or underestimate a driver’s BAC. Overestimation can lead to unjust DUI arrests and convictions, while underestimation may allow impaired drivers to escape detection. Miscalibration may occur if the device is not serviced regularly or if the technician fails to follow proper calibration procedures.

How a DUI Attorney Challenges Breathalyzer Results

Given the potential for inaccuracies in breathalyzer tests, a skilled DUI attorney can challenge the validity of breathalyzer results in court. This challenge is often a critical part of defending against DUI charges, as breathalyzer results are typically central to the prosecution’s case.

Investigating Calibration Records

One of the first steps a DUI attorney may take is to request the calibration records of the breathalyzer device used during the arrest. These records provide details about when the device was last calibrated and whether it was maintained according to Florida law. If there is evidence of improper calibration or a lack of maintenance, the attorney can argue that the breathalyzer results are unreliable and should be excluded from the case.

Questioning the Officer’s Testing Procedure

A DUI attorney can also scrutinize the procedures followed by the arresting officer during the administration of the breathalyzer test. Officers are required to follow specific protocols to ensure the accuracy of the test results. For example, Florida law mandates that officers observe the driver for at least 20 minutes before administering the test to ensure that the driver does not burp, regurgitate, or ingest any substances that could affect the test results.

If the attorney can show that the officer failed to follow these procedures, the breathalyzer results may be deemed unreliable and inadmissible in court.

Highlighting Potential Medical Issues

A knowledgeable DUI attorney can explore whether the driver has any medical conditions that may have affected the breathalyzer results. Conditions such as acid reflux, diabetes, or respiratory issues can lead to elevated BAC readings. The attorney may present medical evidence or expert testimony to show that the test results were influenced by these factors rather than alcohol consumption.

Examining External Factors

In some cases, external factors such as environmental conditions, recent use of mouthwash or medications, or the presence of mouth alcohol can skew breathalyzer results. A DUI attorney may investigate these external factors to demonstrate that the results do not accurately reflect the driver’s level of impairment.

Field Sobriety Tests and Their Role in Florida DUI Cases

In addition to breathalyzer tests, law enforcement officers often administer field sobriety tests (FSTs) to assess a driver’s level of impairment. These tests include the Horizontal Gaze Nystagmus (HGN) test, the Walk-and-Turn test, and the One-Leg Stand test.

While these tests are intended to provide further evidence of impairment, they are subjective and prone to error. A DUI attorney can challenge the results of field sobriety tests by questioning the conditions under which they were administered, the officer’s training and experience, and the driver’s medical or physical conditions that may have affected their performance.

Challenging Field Sobriety Tests

A DUI attorney can argue that factors such as uneven road surfaces, poor weather conditions, or the driver’s nervousness contributed to their inability to perform the tests accurately. Additionally, an attorney may investigate whether the officer followed proper procedures when administering the FSTs. Any deviations from standardized testing procedures can cast doubt on the validity of the results.

Contact Musca Law 24/7/365 at 1-888-484-5057 For Your FREE Consultation

If you are facing DUI charges in Florida and are concerned about the accuracy of breathalyzer tests, it is essential to seek the assistance of a skilled and experienced attorney. Musca Law, P.A. offers a team of experienced criminal defense attorneys with a proven track record of success in handling DUI cases. We provide free consultations 24/7/365 at 1-888-484-5057 and serve all 67 counties in Florida. Protect your rights and your future by contacting Musca Law, P.A. today for expert legal representation.

By understanding the potential flaws in breathalyzer testing and the various ways these results can be challenged, you can better defend yourself against DUI charges and work toward a favorable outcome in your case.