As its name implies, the portable breath test device or preliminary breath test device (PBT)
is a small device similar to ones available in the consumer marketplace to determine
alcohol consumption and a rough approximation of Blood or Breath Alcohol Content
These devices are being increasingly used by law enforcement agencies through out DuPage
County and Illinois.  Their use however is limited at the present time to provide evidence
of probably cause only in the context of a Summary Suspension hearing.  The results
of the PBT are not admissible in the criminal aspect of a DUI trial.

There are two types of PBTs, both designed to measure alcohol on the breath: fuel cell
devices and Taguchi gas sensor devices.  The fuel cell device measures ethanol by
electrochemically oxidizing it or burning it up in a fuel cell.  This oxidation generates
a small amount of electrical current.  The more alcohol the more current.  The gas
sensor devices use small pouous stannic oxide semiconductor elements to attract
breath alcohol increasing electrical conductivity.

Refusing the PBT 

If you have not consumed ANY alcohol and the Police "offer" you a PBT, it may be
tempting to take the test in the hope that they will not make an arrest.  While this
is certainly possible, if the police have taken the DUI stop past the point of
Field Sobriety tests even if the PBT results in a low reading or "triple zero"
there is still a high likelihood that an arrest will still happen.

Taking the PBT test even after no alcohol consumption is made more
risky by the possibility of false positives in this device.  Indeed, mouth
alcohol from breath spray can greatly increase the PBT result.  In addition,
even cigarette smoke on the breath or temperature can affect PBT results.

Accordingly, Brent Christensen always advises clients to politely refuse
a portable breath test. 


Call: 630-665-5965 for more information or

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