The invention relates to an improvement in a breath alcohol test devices includes within the handheld unit containing a fuel cell, a miniaturized self calibrating test device thereby avoiding the need for 30, 60 and 90 day calibration testing. It also relates to various tamper or circumvention improvements...http://www.google.com/patents/US7934577?utm_source=gb-gplus-sharePatent US7934577 - Ignition interlock breathalyzer
