A portable breath test (PBT) is an alcohol sensor that officers carry with them. They will ask a driver to blow into in and it will give a quick indication of whether or not the driver has ingested alcohol. There are certain standards that are required for a portable breath test. More than anything else, I see the portable breath tests being used as a way to get a driver to submit to other forms of testing so that they can ultimately get them to submit to the breathalyzer at the station. There are a lot of issues with the portable breath tests, particularly in regards to maintenance. There are also a lot of factors that need to be considered when an officer gives a portable breath test. A lawyer should be aware of these factors in order to effectively cross-examine someone about the use of a PBT.