Preliminary Breath Tests

A handheld preliminary breath test (aka PBT) is often used to by an officer to make an arrest decision in a DUI case. These devices are inaccurate, typically inadmissible, and should not be relied on.

PBT’s are handheld breath testing devices that are used in the field.  They are different then the breath machines used at the police station.  They are smaller and typically have an LCD readout.  Unlike the large station breath machines, PBT’s lack the ability to print out the result.

PBT’s are used solely for the purpose of aiding the officer in making his decision of whether or not he is going to arrest someone for DUI.  The results are not admissible in court.  Thus the prosecutor and the police cannot use PBT results against a DUI defendant in trial.   In many states, such as Arizona, a DUI suspect has an absolute right to refuse to submit to a PBT and the refusal cannot legally be held against them.  Check your local laws to determine whether you may refusal a PBT without penalty in your state.

If you are pulled over for DUI, you should not submit to a PBT, even if you believe you are under the legal limit.  The results are inaccurate and can produce falsely elevated readings.  If there is no penalty for refusal you have nothing to lose by electing not to submit to the test.  If you refuse, the officer may still arrest you.  However, if you blew above the legal limit you would be arrested anyway.  It is better in such a situation to let a blood test sort it out.

PBTs are good party entertainment, and can be very useful in determining whether there is alcohol present in a person’s system.  They are not, however, reliable for purposes of measuring a specific alcohol level, and they are not designed to detect impairment.

The most common PBTS are the Intoxilizer 300 and the Alco-Sensor.