A Georgia DUI breath test does not necessarily produce one single number. When the State chooses evidential breath testing, Georgia law requires the operator to request two sequential breath samples. Those samples may produce slightly different alcohol concentration readings, and the fact that they are not identical does not automatically make the test invalid.
What matters is how far apart the results are, whether both samples qualify as adequate, whether the instrument and operator met Georgia’s requirements, and how the readings are used in the criminal and administrative parts of the case.
For someone facing a DUI charge, two different numbers can be confusing. The lower number may carry special legal significance, while a larger gap between the samples can create a separate admissibility issue.
Georgia Requires Two Sequential Breath Samples
Under O.C.G.A. § 40-6-392, when the State selects breath testing, two sequential breath samples must be requested. Georgia defines an adequate breath sample as one sufficient for the instrument to produce a printed alcohol concentration analysis.
The Georgia Bureau of Investigation Implied Consent program oversees the state’s breath alcohol testing program. The GBI approves evidential testing devices, certifies operators, approves testing methods, and oversees periodic inspections. The GBI currently identifies the Intoxilyzer 9000 as Georgia’s approved evidential breath testing instrument.
That means a proper defense review involves more than looking at two numbers. Barton DUI Law discusses those broader issues in its guide to how breath and blood test results are challenged in DUI defense cases.
The Results Do Not Have to Match Exactly
Georgia law anticipates that two sequential samples may produce different readings. The important statutory limit is 0.020 grams.
For either or both sequential results to be admissible in the State’s case in chief, the two readings may not differ by more than 0.020 grams. The statute also says the lower of the two results is determinative for accusation and indictment purposes and for administrative license suspension purposes.
For example, imagine readings of 0.091 and 0.104. The difference is 0.013. Because that spread is not greater than 0.020, the results satisfy this particular comparison requirement.
Georgia does not require two perfectly identical readings. It sets a limit on how far apart they may be.
What If the Results Differ by More Than 0.020?
A larger difference changes the analysis.
Suppose one sample is 0.082 and the next is 0.106. The difference is 0.024. That exceeds the statutory limit. Under O.C.G.A. § 40-6-392, either or both readings from that sequential pair face an admissibility problem in the State’s case in chief when the difference is greater than 0.020.
Georgia law also limits how many testing series the State may request. It permits no more than two sequential series of two adequate breath samples each. The State therefore cannot simply continue requesting complete series indefinitely in search of another result.
The 2024 Georgia Court of Appeals decision State v. Youn examined how this statutory limit operates. The court focused on whether samples were legally adequate and how many complete testing series had actually been requested.
Why the Lower Reading Matters
When two qualifying readings are different, Georgia law gives the lower result a specific role.
The lower result controls for accusation and indictment purposes and for administrative license suspension purposes. That becomes especially important when the readings fall on opposite sides of a legal threshold.
For most drivers age 21 and older, Georgia’s per se DUI threshold is 0.08. Commercial drivers and drivers under 21 are subject to different thresholds. Barton DUI Law provides a broader explanation of Georgia DUI blood alcohol concentration limits.
Consider an adult noncommercial driver with readings of 0.079 and 0.094. The difference is 0.015, so the pair falls within the 0.020 spread requirement. But the lower reading is below 0.08. Because the statute gives the lower result special significance for charging and administrative purposes, that difference can matter substantially.
It does not necessarily end the entire DUI case. Georgia also recognizes DUI theories that do not depend solely on a per se 0.08 result. Driving evidence, officer observations, field sobriety testing, video, statements, and other evidence may still become part of the prosecution’s case.
Can Both Results Be Used in Court?
When sequential results satisfy the statutory requirements, Georgia appellate courts have recognized that both readings may be admitted. The statute does not require that only the lower number be shown at trial simply because the lower result controls certain charging and administrative decisions.
That distinction matters. The lower result has a specific legal function, but the complete breath test record may still be relevant when evaluating the prosecution’s evidence.
A DUI attorney may therefore examine both results, the timing of each sample, the test printout, instrument messages, and the complete sequence rather than focusing only on the highest number.
Different Numbers Do Not Explain Why They Differed
A difference between two samples does not, by itself, establish why the results were different.
The gap should be considered alongside the timing of the samples, whether both were adequate, whether the instrument reported error messages, and whether the equipment and operator met Georgia’s requirements.
Georgia law requires chemical analysis to be performed according to methods approved by the GBI Division of Forensic Sciences, on a properly functioning instrument, by an individual holding a valid permit. The Georgia rules governing implied consent testing also require approved breath testing instruments to be periodically checked for calibration and operation.
The GBI states that evidential breath testing instruments are inspected once every calendar quarter. A meaningful review therefore goes beyond subtracting one reading from another.
What If One Sample Is Not Adequate?
A different issue arises when the machine produces a printed result for one sample but the second attempt does not produce an adequate sample.
Georgia law defines an adequate sample by whether the instrument produces a printed alcohol concentration analysis. The statute also provides that a later failure or refusal to provide an additional adequate sample does not automatically affect the admissibility of a prior adequate sample.
Georgia appellate courts have addressed cases in which one adequate sample was obtained but another was not. Those situations are legally different from two adequate samples that both produce numerical readings and are more than 0.020 apart.
This distinction is important when reviewing an Intoxilyzer printout. Two different numerical results and one result followed by an insufficient sample should not automatically be treated as the same testing scenario.
Why Test Printouts and Instrument Records Matter
A defense attorney may review materials showing exactly what occurred during the testing sequence. Depending on the case, that can include:
- The breath test printout
- The exact time of each sample
- The instrument identification
- Any error or status messages
- The operator’s permit status
- Periodic inspection documentation
- The number of adequate samples obtained
- Whether another testing series was requested
The GBI’s program is responsible for operator certification, approved testing methods, and periodic instrument inspections. Georgia law also provides that, upon request, full information concerning the State administered chemical test must be made available to the person tested or that person’s attorney.
Barton DUI Law explains the importance of procedural review in its article on faulty police procedure in Georgia DUI cases.
A discrepancy does not automatically guarantee that breath evidence will be excluded. Its significance depends on what happened and which legal requirement is involved.
Breath Results Can Affect the License Case Too
Breath test results may affect more than the criminal DUI prosecution.
Georgia’s statute specifically says the lower of two qualifying readings is determinative for administrative license suspension purposes. That makes the exact pair of numbers important when reviewing administrative action involving driving privileges.
Barton DUI Law’s information on the Georgia DUI 30 Day Rule explains the short deadline that may apply when a driver needs to challenge an administrative license suspension.
The criminal case and the administrative license matter are related, but they are not the same proceeding. A driver should not assume that an issue raised in one automatically resolves the other.
An Independent Chemical Test May Also Matter
Georgia law allows a person who submits to the State’s chemical test to obtain an additional chemical test from qualified personnel of the person’s own choosing and at the person’s expense.
That right can become important when the State’s breath testing is disputed. The statute also provides that the arresting officer must advise the person of the right to additional chemical testing.
Whether that right was properly explained and whether a requested independent test was reasonably accommodated can become another part of the overall defense review.
What Should Be Reviewed When Two Results Are Different?
When two breath readings are different, a complete review may ask:
- Were both samples sequential and legally adequate?
- What was the exact difference between the readings?
- Did the difference exceed 0.020 grams?
- Which result was lower?
- Did the lower result cross an applicable legal threshold?
- Was another testing series requested?
- How many adequate samples were obtained in total?
- Did the instrument produce any error messages?
- Did the operator hold a valid permit?
- Had the instrument received required periodic inspection?
- Was an independent chemical test requested?
- How does the breath evidence compare with video, driving observations, and other evidence?
A breath test printout is evidence to analyze, not a final answer by itself.
Different Breath Results Can Change the Legal Analysis
Georgia law specifically addresses what happens when two sequential breath samples are not identical.
If the readings are within 0.020 grams of each other, the difference alone does not invalidate them. The lower result has special significance for accusation, indictment, and administrative license suspension purposes. If the readings differ by more than 0.020, admissibility becomes a much more important question and the full testing sequence should be reviewed.
Those details can be especially significant when the lower and higher readings fall on different sides of a statutory threshold.
Barton DUI Law reviews Georgia DUI cases involving breath testing, chemical test evidence, and license consequences. If your Intoxilyzer paperwork shows two different results, contact Barton DUI Law to have the testing sequence and the rest of the evidence reviewed before assuming what those numbers mean for your case. Barton DUI Law’s office is located in Stockbridge and represents clients across multiple Georgia counties.
This article is for general educational purposes and does not constitute legal advice. Georgia DUI cases are fact specific, and current law should be applied to the individual circumstances of each case.
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