There are numerous different ways to challenge the breath test device in court. Again good a counsel will be looking at whether or not the instrument was working properly at the time. Whether or not the test was administered within compliance to rules. Whether or not that instrument was properly calibrated and functioning properly during its maintenance inspections both monthly and yearly. Again whether or not that instrument is showing compliance with the department rules is the major question to determine the admissibility of a breath test in the state of Florida.