| 摘要 |
A breath tester, in two embodiments, employing an alcohol detecting element (e.g. a zinc oxide semiconductor element) which, prior to use, is purged by pumping ambient air across it and maintaining it at a higher than normal operating temperature. In use, after a purging period the air pumping is stopped and the detector heaters are turned off, while breath is directed to the detector and any resulting change in properties (conductivity/resistivity) is sensed and signaled. The first embodiment is largely manually operated and uses a meter to signal both the breath alcohol concentration, and also the purged state of the detecting element. The second embodiment is largely automatic, includes timers and interlocks to prevent misuse, and employs lights to signal its outputs ("fail," for over one BAC level, "warn" for over a lower BAC level and "pass" for under that level) as well as its operational status ("power" on, "wait," "ready," "test"). Both embodiments may be battery powered and means for sensing and signaling the charge level on the batteries is disclosed. |
