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How Breath Test Calibration Affects Your Ohio DUI Case

Breath Test Calibration

Usually, if you have been ordered by a police officer to take a test to measure your blood alcohol concentration (BAC), you will be given the breathalyzer test because it is generally the fastest and cheapest way for the police officer to measure your BAC. If your results are .08% or higher, you are over the legal limit and will be arrested for driving under the influence under Ohio Revised Code section 4511.19.

However, it may be possible to argue that the breathalyzer machine was not properly calibrated, thus leading to inaccurate results.

Ohio uses multiple approved breath-testing devices: the BAC Datamaster, BAC DataMaster K, BAC DataMaster CDM; Intoxilyzer 5000 series 66, 68, and 68 EN; and the Intoxilyzer 8000. While the law enforcement officer may also use a handheld breath test device to give you a breath test, the results from such a device are not admissible in court as evidence of a DUI offense.

Why Are Breath-Testing Machines Calibrated?

In Ohio, the breath-testing machines are calibrated when they are first built so that they will be able to accurately identify and quantify alcohol. However, law enforcement agencies using the machines must also periodically run calibration checks to ensure that that the breath-testing machines are still producing accurate results.

These periodic tests are generally done at least once per week in Ohio by law enforcement agencies using a simulator and a solution of water with a known concentration of alcohol, which is then heated to 32 degrees Celsius, or the average temperature of human breath. When the vapor forms above the liquid, it is pushed through the machine, which should produce a result identical to the known concentration of alcohol in the test solution.

The Ohio Department of Health is responsible for devising the testing method for the admissibility of breath tests.

The Ohio Administrative Code regulates the use of breathalyzer machines. Ohio Administrative Code chapter 3701-53 requires the calibration checks to be performed at least once every seven days by an individual with a valid senior operator permit issued by the Ohio Director of Health. The calibration check’s results must be within .005 of the known concentration of the test solution, which must have been from a refrigerated bottle which has been used less than 90 days and from a batch which is less than one year old. The law enforcement agency must also keep the results of these weekly instrument checks for at least three years.

The new regulations in O.A.C. 3701-53-04 also provide for new standards to automatically perform a dry gas control test before and after every subject test and instrument certification using a dry gas standard.

What Happens if the Breathalyzer Machine is Not Maintained?

If the law enforcement agency fails to maintain the breathalyzer test machine according to the regulations in the Ohio Administrative Code, any breathalyzer results from that machine will not be admissible in court, meaning that the prosecutor would likely have to either drop the charges or offer lesser charges instead of a DUI offense. If the DUI defense lawyer does file the appropriate motion to suppress these results, the prosecution is then required to affirmatively prove that the law enforcement agency in question did properly comply with the Ohio Administrative Code regulations. If the prosecution fails to prove this substantial compliance with the regulations, the results of the breathalyzer test are then excluded.

DUI Charge & Breath Test Calibration

While preparing a defense for a DUI charge, your attorney should request the batch and bottle certificate for the calibration tests used on the breathalyzer machine used to give you a breath test, in order to verify compliance with the Ohio Administrative Code’s testing requirements.

The Ohio Revised Code section governing DUI arrests, O.R.C. section 4511.19(D) establishes a three-hour limitation on testing your breath for alcohol. The period begins at the time of the violation instead of at the time of arrest. Under O.R.C. section 4511.19(A)(1)(b)-(i), if the breath test is not conducted within this three-hour period, the results of the test could be inadmissible in court to support the prosecution’s DUI charge against you.

The time of the violation occurring, which starts the three-hour limitation period, is most commonly determined by the time of the traffic stop. However, the time is especially important if the DUI arrest results from an auto accident, where prosecutors fail to establish definitively when the accident occurred.

Finally, the samples must be analyzed according to the breath test machine’s operational checklist.

Challenging Breath Test Results

To challenge the results of a breath test, a good Ohio DUI defense lawyer will often challenge the admissibility of the breath test or its results, by filing a motion to suppress the breathalyzer test after reviewing the records for the machine, especially if there is any record of an improperly-performed breathalyzer test.

Your attorney could argue improper testing, improper calibration, inadequate record-keeping, improper operator, radio frequency interference, or other defenses if there is any doubt about the calibration, maintenance, or operation of the breath test machine used to give you your breath test.