Questioning Breathalyzer Calibration

If police stop you for suspected drunk driving, they may ask you to blow into a breathalyzer to check for intoxication. A breathalyzer is a device that analyzes your breath to determine the amount of alcohol and whether you are over the legal limit for driving. The police officer could use this test as enough evidence for probable cause to make an arrest.

At the police station, they may ask for another breath sample using a larger breathalyzer device. This BAC level is evidence to use against you for criminal DUI charges. When a breath test device isn’t correctly calibrated, it can lead to a wrongful arrest and conviction.

If you have questions about breathalyzer machines and their accuracy, talk to a criminal defense attorney for legal advice.

Can a Breathalyzer Be Wrong?

A breath testing device measures estimated blood alcohol concentration (BAC). It calculates the BAC based on a lung air sample and detects ethanol with fuel cells or spectroscopy. The breath alcohol measurement is displayed as BAC. If the BAC test results are over 0.08%, drivers are generally considered impaired.

This figure is an estimate. The actual amount of alcohol in your body can vary widely over time and from person to person. It also is subject to change due to respiration rate, body temperature, and other factors.

Breathalyzer readings are generally not as reliable as a blood test. It gives a general estimate of your blood alcohol content. Some of the reasons why the results of a breathalyzer test can be wrong include:

Other Substances Containing Alcohol

Sometimes, alcohol-containing substances in a person’s mouth can give off a high reading. This can happen with some cold medicines, mouthwash, or acid reflux. Police are usually supposed to watch a driver for a certain amount of time before giving the test. This ensures that they do not regurgitate or put anything in their mouth that may give a false result.

Improper Calibration

A frequent issue with breathalyzer accuracy is that the device is not in proper working order. Breathalyzers must have regular calibration and all required maintenance for accurate results. An improperly maintained machine can produce unreliable test results. Without regular recalibration, your defense lawyer can question the accuracy of your BAC results.

How Often Are Breathalyzers Wrong?

While breath testing devices are sometimes accurate, they can also be wrong. Breath test device results can be inaccurate if the law enforcement officer doesn’t follow proper procedures. The officer should perform multiple breath tests to ensure a reliable result.

Breathalyzer results can also be wrong if the driver has residual alcohol in their mouth, doesn’t blow out a full breath, or has certain medical conditions. Talk to a DUI defense attorney to learn more about what can give inaccurate BAC results.

How Often Should a Breathalyzer Be Calibrated?

Each state has its own breathalyzer calibration laws. In California, law enforcement must recalibrate breathalyzers every 10 days or 150 uses, whichever comes first. However, there are some basic guidelines that most states follow to ensure that the device’s results hold up in court. They include:

• Check the breathalyzer for accuracy at specific intervals and maintain it properly
• The officer administering the test must be certified in the use of a breathalyzer
• The officer performs breath tests in accordance with their training
• The test must consistently give two readings or more that are within .02% of each other

Is It Bad to Refuse a Breathalyzer?

You can technically refuse a breathalyzer, but it is not always the best idea. Driving is a privilege, not a right. If you refuse a test, states can take administrative action to suspend your driver’s license. Even if you refuse to take the test, the police may arrest you anyway.

The prosecutor can still convict you of a crime without evidence that you were over the limit. There is other evidence to show you were driving while impaired. The prosecutors can use the officer’s observations, other witnesses, or field sobriety test results as evidence.

Are Breathalyzers Admissible in Court?

If you can show that the police did not follow the proper procedure when using the breathalyzer, the judge may determine that the breathalyzer results are inadmissible as evidence. Your attorney can file a motion to suppress and keep unfair evidence out of court.

Your attorney can request police records, including the maintenance and calibration records. Your attorney can show that the breathalyzer was not calibrated as required. Then, the prosecution must prove that you were intoxicated using other evidence.

How Can A DUI Attorney Help?

If you are facing a DUI charge, one of the primary pieces of evidence used against you is the breathalyzer test results. A qualified DUI attorney is familiar with local DUI laws and breathalyzer requirements. Contact a DUI defense lawyer to help you question breathalyzer results after a drunk driving arrest.