This page was written, edited, reviewed & approved by Brian LaVine following our comprehensive editorial guidelines. Brian LaVine the Founding Partner, 10+ years of legal experience as criminal defense attorney.
If the breathalyzer was not properly calibrated, your breath test readings may be wrong, and the court could throw them out. A breathalyzer is a sensitive instrument that requires regular calibration to operate correctly. Forensic studies indicate that breath-test margins of error can exceed 15% even under normal conditions.
According to the National Highway Traffic Safety Administration (NHTSA), maintaining a Conforming Products List for calibrating units is essential for ensuring device reliability. Thousands of DUI cases have been overturned in states like Massachusetts and New Jersey due to massive calibration scandals involving withheld maintenance records.
The legal consequences of a DUI conviction include jail time, fines, and driver's license suspension. The prosecution assumes the breathalyzer worked correctly, but a skilled defense attorney can challenge this assumption. At LaVine Law Firm, we examine the science behind every arrest and fight to protect your driving privileges.
A breathalyzer test measures the ethanol in your breath to estimate your blood alcohol concentration. Most breath-testing devices employ infrared spectroscopy or fuel-cell sensors to detect alcohol molecules. These machines need precise tuning to convert a breath sample into an accurate BAC reading. Your breathing patterns during the test can also affect the results.
Understanding what happens if the breathalyzer is not properly calibrated is crucial: without proper calibration, the device cannot distinguish among different alcohol levels. The American Bar Association notes that several factors, including internal chemistry and environmental interference, can lead to inaccurate and potentially unfair readings.
The breathalyzer machine contains delicate sensors that detect alcohol vapor in your breath. Temperature and humidity affect the performance of these sensors. Law enforcement agencies must store and use devices within specific conditions to ensure accuracy. The machine also needs regular cleaning to prevent residue that could cause false readings. When officers omit proper maintenance steps, such as checking the breath test equipment's sensors for residue, the device may produce inaccurate results.
Texas law sets strict requirements for how often breath-testing devices must be calibrated. Under the Texas Department of Public Safety (DPS) regulations, breathalyzers must undergo regular calibration checks using certified reference solutions. Officers must record each calibration in detailed maintenance logs. When agencies fail to comply with these official law requirements, breath test results may be inadmissible in court.
Even a small error in the reference solution used during maintenance can cause big problems. The device may display breath-test results with falsely elevated BAC readings. A machine that reads just 0.01% too high could push someone over the legal limit when they were actually under it. Because DUI penalties are severe, these errors can change the course of someone's life.
Calibration records document the condition of the breathalyzer over time. These documents show when the device was tested, the readings obtained, and who performed the work. Gaps in records suggest the machine may have run without proper checks. A DUI defense attorney reviews these logs to find times when the device was out of compliance. Missing or incomplete records raise serious questions about whether your first-time offense data is actually reliable.
Sensor drift occurs when a breathalyzer gradually loses accuracy between scheduled maintenance dates. The alcohol-detection sensors may degrade or become contaminated over time. This drift means the machine may read higher or lower than the true blood alcohol content. By the time the next calibration reveals the problem, the device may have produced hundreds of faulty readings. We investigate whether drift affected your readings and use this evidence to challenge your DUI charge.
If a DUI lawyer can prove the breathalyzer device was faulty or affected by calibration errors, they can file a motion to suppress the evidence. This renders the breath-test results inadmissible and deprives the prosecution of its principal evidence. Without reliable blood alcohol concentration (BAC) evidence, the state struggles to prove drunk driving charges. Several legal defenses exist to challenge breathalyzer results, including maintenance and calibration records. These defenses provide valid grounds for getting your case dismissed.
Your attorney can subpoena the maintenance and calibration records and usage logs for the device used in your case. These documents reveal gaps in service, missed calibration dates, or readings outside normal ranges. We seek any period during which the machine operated without proper checks or failed to undergo regular calibration before your traffic stop. A blood test may provide more reliable evidence, but many cases rely only on breath tests. Records showing the device was not calibrated correctly support a motion to exclude the evidence.
Expert witnesses play a crucial role in explaining calibration issues and environmental factors to judges and juries. Toxicologists can testify about how improper calibration and external influences affect breathalyzer accuracy and reduce the test's reliability. These experts translate complex science into terms that non-scientists can understand. At LaVine Law Firm, we work with qualified experts who help juries see why the breathalyzer results cannot be trusted, given the circumstances surrounding your arrest. Their testimony often creates reasonable doubt, leading to favorable outcomes.
Calibration is only one piece of the puzzle when challenging breathalyzer evidence. Biological and environmental factors can also mislead the machine into reporting false readings. Your body chemistry and certain medical conditions may cause the device to overestimate your BAC. Law enforcement officers also use field sobriety tests to gather other evidence, but these tests have their own problems. A qualified DUI attorney examines all the facts and the circumstances surrounding your test to build a complete defense.
Acid reflux and gastroesophageal reflux disease can introduce mouth alcohol into the testing chamber. When stomach contents rise into your throat, they bring alcohol vapor that mixes with your breath sample. This residual alcohol causes a false spike that does not reflect your true BAC. The law enforcement officer should observe you for 15 minutes before testing to ensure no burping or reflux occurs. If the officer failed to follow proper procedures or follow proper protocol, we challenge the results.
Certain medical conditions can cause inaccurate results even when the breathalyzer device is functioning properly. Diabetes and low-carb diets cause your body to produce ketones through ketosis. Some breathalyzer machines mistake the isopropyl alcohol in ketones for ethanol. Breath fresheners and certain medications can also change readings. We check whether any medical conditions or other environmental factors led to your falsely elevated BAC readings.
Building a strong defense against breathalyzer evidence takes a step-by-step approach. We follow these steps to find flaws in the state's case:
A conviction leads to license suspension, heavy fines, and possible jail time. We work hard to help you avoid these outcomes.
How often must a breathalyzer be calibrated?
Most states require calibration every 30 days or after a set number of tests. Rules vary by state, so your DUI defense lawyer will check local laws, including Missouri law if applicable.
Can I see the calibration records for my test?
Yes. Your defense attorney can get maintenance logs and calibration records through discovery. These are public records you have a right to review.
Does acid reflux really affect the test?
Yes. Acid reflux brings alcohol vapor from your stomach into your breath. This inflates results and can unduly push readings above the legal limit.
What if the officer wasn't certified?
If the officer's certification expired or never existed, the court may throw out the breathalyzer results. Proper training is required to give chemical tests.
Is a portable breathalyzer as accurate as the station one?
Generally no. Portable units are subject to less oversight and are often not admissible as primary evidence. Station devices must meet stricter calibration standards.
Can a case be dismissed if the machine was faulty?
Yes. If the court throws out the breath test evidence due to calibration issues, the prosecution often lacks enough proof to continue. Many DUI cases get dismissed this way.
Technical details can make or break a DUI case. The distinction between a conviction and a dismissal often turns on whether the breathalyzer was properly maintained to produce accurate results. We serve clients throughout Texas who face drunk driving charges based on questionable breath test evidence. Our team knows how to find the flaws that can save your driver's license and keep you out of jail.
If you wonder what happens if the breathalyzer is not properly calibrated, you need a team that understands the science and the legal process. Contact LaVine Law Firm today for a free consultation and let us review your breath test data. We will examine every detail of your case to build the strongest possible defense. Your future deserves a thorough look at the evidence against you.
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