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PBT Test: What a Preliminary Breath Test Means for Your Georgia DUI Case
What Is a PBT Test?
A PBT test – short for preliminary breath test – is a handheld, roadside breath-alcohol screening device. Officers use it during DUI investigations to detect alcohol before deciding whether to arrest. What is a PBT test in practical terms? It is one more data point the officer gathers at the roadside. It comes after the driver performs standardized field sobriety tests.
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During a Georgia DUI stop, the officer may ask the driver to blow into a small PBT device. The device is portable – roughly the size of a large flashlight. You may also hear it called a roadside breath test. The result helps the officer decide whether to arrest the driver. It also helps the officer decide whether to request a formal chemical test at the station.
A PBT is not the final word on a driver's blood alcohol concentration. It is a screening tool. Understanding that distinction matters for anyone facing a Georgia DUI charge.
How a PBT Device Works
When an officer administers a PBT, the driver blows into a disposable mouthpiece. The mouthpiece attaches to the handheld unit. Inside the PBT machine, a fuel cell or semiconductor sensor reacts with the alcohol vapor in the breath sample. This reaction produces an estimated breath alcohol concentration.
Depending on the model the agency uses, the display may show a numeric reading. It may also show a simple pass or warn or fail indicator. Neither type of result is as reliable as the evidential instrument used at the station after arrest.
Before administering the test, the officer should observe the driver for a set period. This observation helps ensure that mouth alcohol from a recent drink, belch, or other source does not skew the reading. Georgia's testing statute sets standards for the chemical test used as evidence, not for the handheld roadside screener. That analysis must follow methods approved by the GBI Division of Forensic Sciences, run on a machine in good working order by an operator holding a valid division permit. Observation periods and maintenance schedules for a PBT device come from agency policy and the manufacturer instead.
PBT vs Breathalyzer: What's the Difference?
The phrase "PBT vs. Breathalyzer" comes up often. People use "Breathalyzer" loosely for any breath test. In a Georgia DUI context, however, there are two very different devices. Mixing them up can cause confusion about rights, consequences, and admissibility.
The first device is the PBT: a portable screening tool used at the roadside before arrest. The second is the evidential breath-testing instrument. It is commonly an Intoxilyzer machine, and it is used at the jail or police station after arrest. When the state chooses breath testing, the statute requires two sequential samples, and the two readings may not differ by more than 0.020 grams for either one to be used in the state's case.
| Feature | PBT (Roadside) | Evidential Breath Test (Station) |
|---|---|---|
| Location | Roadside, during the stop | Police station or jail, after arrest |
| Purpose | Screen for alcohol; help establish probable cause | Produce an evidentiary BAC result |
| Calibration standards | Agency policy and manufacturer guidance – the testing statute sets none | Approved methods, a permitted operator, and an instrument in good working order |
| Admissibility | Generally limited – Georgia courts have historically treated PBT numeric results differently than evidential results | Admissible as substantive evidence when performed by approved methods and a permitted operator |
| Implied consent consequences for refusal | None – implied consent reaches the test requested after arrest | Refusal means a one-year license suspension, subject to a hearing request |
Because the PBT is a screening tool with looser technical standards, its numeric result does not carry the same evidentiary weight. The station instrument carries more weight. Georgia's testing statute sets the conditions for a chemical analysis to be valid as evidence – approved methods, a permitted operator, and a machine in good working order. What a roadside PBT number may be used for comes from court decisions applying that standard, not from the implied consent statute. Georgia's Court of Appeals has said the roadside device shows only whether alcohol is present. It does not measure how much alcohol is in a driver's blood. Its job is to help the officer decide whether there is probable cause to arrest.
Is a PBT Test Required in Georgia?
One of the most common questions drivers ask is whether they must blow into the roadside PBT device. Georgia's implied consent law reaches the chemical test an officer requests after arresting a driver, so it does not reach the roadside screening device. The PBT is therefore distinct from the post-arrest evidentiary breath, blood, or urine test. Georgia's implied consent statute is what governs that post-arrest test.
The two tests carry different consequences. The implied consent notice is read when the arresting officer requests the state-administered chemical test – after an arrest, or after a crash causing serious injuries or a death – so refusing the roadside PBT brings no license suspension. Refusing that state test means the Department of Driver Services suspends the license for one year. The notice also warns that a refusal of blood or urine testing may be offered into evidence at trial, and that a driver who submits may get additional tests at his or her own expense from personnel of his or her own choosing.
Two important points to keep in mind:
- Refusing the roadside PBT does not necessarily stop the officer from arresting a driver. The officer can rely on other observations. These include the odor of alcohol, slurred speech, driving pattern, and field sobriety test performance to establish probable cause.
- The decision to submit to or refuse the state-administered chemical test after arrest carries license consequences. A driver who wants a hearing on that suspension must request one in writing within 30 days, with a $150.00 filing fee.
Because every stop is different, drivers should speak with a Georgia DUI lawyer about their specific situation. Do not rely on general information alone.
How Accurate Is a PBT Test?
Handheld PBT devices have well-documented limitations. These limitations are a core reason courts treat the PBT as a screening tool. They do not treat it as a definitive BAC measurement.
Factors that may affect accuracy include:
- Mouth alcohol. A recent drink, mouthwash, or even a burp can leave residual alcohol in the mouth. This residual alcohol may inflate the reading if the officer did not observe the driver long enough before administering the test.
- Gastroesophageal reflux (GERD). Drivers with acid reflux conditions may produce elevated readings. Stomach vapors reach the mouth in these cases.
- Calibration drift. Like any sensor-based instrument, a PBT device can drift from its calibrated baseline. This happens over time if the device is not maintained on schedule.
- Environmental conditions. Temperature extremes and humidity can affect some sensor types.
- Operator error. If the officer does not follow proper procedures – skipping the observation period, for example – the result may not reflect actual breath alcohol.
These factors do not mean every PBT reading is wrong. They do mean the result should be evaluated carefully. Attorneys and drivers who want specific accuracy data should look to manufacturer documentation. They should also look to peer-reviewed literature and published appellate decisions. Do not rely on approximations.
How a PBT Result Can Affect Your Georgia DUI Case
A PBT result can play several roles in a Georgia DUI prosecution. This depends on the facts of the stop and the current state of the law.
First, the PBT result may support the officer's probable cause to arrest. If the officer's report states that the PBT indicated the presence of alcohol, the prosecution may use that fact. It may use it along with other observations to argue the arrest was justified.
Second, the PBT result can be challenged. Common defense angles include:
- Observation period. Did the officer watch the driver for as long as the device manufacturer and agency policy direct before administering the test? If not, mouth alcohol may have contaminated the sample.
- Device maintenance records. Was the PBT device calibrated and maintained according to agency policy and manufacturer guidelines? Gaps in the maintenance log can undermine the result's reliability.
- Operator training. Was the officer trained and certified to use the specific PBT model? Lack of training may call the result into question.
- Voluntariness. Did the driver consent to the PBT voluntarily? Or did the officer's words or conduct create the impression the test was mandatory?
Third, the way the numeric result is used – or excluded – at trial depends on current Georgia law. It also depends on the judge's rulings on foundation and reliability. The distinction between admissibility for probable cause purposes and admissibility as substantive BAC evidence can be significant.
Outcomes depend on the specific facts. Nothing in this article should be taken as a guarantee that any particular challenge will succeed. Every case is different. Results depend on the circumstances.
Frequently Asked Questions About PBT Tests
What Does PBT Stand For?
PBT stands for preliminary breath test. It refers to the handheld breath-alcohol screening device officers use at the roadside during DUI investigations. The term distinguishes this portable screening tool from the larger evidential breath-testing instruments used at the police station after arrest.
Can I Refuse a PBT Test at a Georgia Traffic Stop?
Georgia's implied consent law reaches the chemical test an officer requests after an arrest, so no license suspension follows a refusal of the roadside PBT. It is separate from that post-arrest chemical test, where a refusal means a one-year license suspension. However, refusing the PBT does not prevent the officer from arresting you based on other evidence. Consult a Georgia DUI attorney about the specific consequences that may apply in your situation.
Is a PBT Result Admissible in a Georgia DUI Case?
Georgia courts have historically treated PBT numeric results differently from evidential breath test results. Georgia's testing statute makes a chemical analysis valid as evidence only when it follows methods approved by the GBI Division of Forensic Sciences, on an instrument in good working order, run by a permitted operator. What a PBT reading can be used to prove comes from court decisions applying that standard, not from the implied consent statute. Georgia's Court of Appeals has said the roadside device shows only whether alcohol is present. It does not measure how much alcohol is in a driver's blood. Ask a Georgia DUI attorney how those decisions apply to the facts of your stop.
What's the Difference Between a PBT and the Breathalyzer at the Police Station?
The PBT is a portable screening device used at the roadside before arrest. The instrument at the station is a larger, more precisely calibrated evidential machine. It is designed to produce a BAC result that can be admitted as substantive evidence at trial. The two serve different purposes and are subject to different standards.
How Accurate Is a Handheld PBT Device?
Handheld PBT devices can be affected by mouth alcohol, calibration drift, temperature, and operator error. These limitations are why the PBT is treated as a screening tool rather than a definitive measurement. The accuracy of any particular reading depends on the device model, maintenance history, and the conditions under which it was administered.
Talk to a Georgia DUI Defense Attorney About Your PBT Result
A PBT result at the roadside is often the start of a DUI case – not the end. The reliability of the device can be examined. The officer's procedures can be examined. The circumstances of the stop can be examined. A defense lawyer who understands how Georgia DUI cases are built and challenged can do this work.
If you received a PBT test during a traffic stop and now face a DUI charge, consider reaching out to Kohn & Yager LLC for a consultation about your case. During an initial call, you can discuss what happened during your stop. You can discuss what tests were administered. You can discuss what steps may be available to protect your driving privileges and your record.
Every case turns on its own facts. Contact Georgia Criminal Defense to discuss your situation with an attorney who handles DUI cases in Georgia courts.
