The breath test procedures in Pennsylvania for a DUI are often overlooked by Chester County DUI lawyers, despite the fact that they may be potential avenues for beating a case. According to the Pennsylvania Code, Section 77.25(b), for test results for a breath test any Chester County DUI must be disregarded and the breath test removed from service if,
1) the difference between the results of the two actual alcohol breath tests is .02 or more, for machines read to the second decimal place, or .020 or more for machines read to the third decimal place, or
2) the simulator test yields a result less then .09% or greater then .10% when the breath test device is read to the second decimal place, or if the simulator test yields a result less then .090% or greater then .109% when the breath test device can be read to the third decimal place.
This section is covered under the Pennsylvania code 77.24(b). In order to comply with the statute and regulations, the Commonwealth must show that two consecutive actual breath tests were performed. Two consecutive actual breath tests were not obtained in the case of Commonwealth v. Stoops, when one breath test did not perform and "air blank" test and the other did. When a defendant took only one breath test and refused the second, the requirements were not met. This is the case of Commonwealth v. Diulus from 1990.
Certificates of calibration accuracy or only presumptive evidence of proper testing for accuracy. They are not presumptive evidence of the accuracy of breath test results, injury instructions to that effect were reversible error. This is the case of Commonwealth v. Sloan. In this particular case, the jury should have been instructed that if they believed the test results were reliable, they could draw all reasonable inferences from the results of the Intoxilyzer test, but they should have been cautioned that the test is only evidence of the defendants intoxication and the test results does not require such a finding.