Abstract: A method and apparatus for measuring user breath alcohol concentration. A flow of an expired breath sample is passed through a fuel cell sensor giving an output signal proportional to the amount of alcohol present in the sample. By measuring pressure, the volume of the sample may be calculated by integrating pressure over expiration time of the sample, whereas breath alcohol concentration is calculated based on the fuel cell output signal. Both sample volume and breath alcohol concentration values are continually updated by integrating measured instantaneous pressure and fuel cell output signal over time, irrespective of breath sample volume. When the user stops blowing, volume compensation is performed to obtain a compensated fuel cell output signal using a stored calibration volume. Hence, an improved method for accurately measuring breath alcohol concentration of a user is achieved, capable of handling varied expired volumes of breath, obviating the need for sampling mechanism.

Abstract: A system operable to determine a future point of time, at which the alcohol concentration in blood of a user is less than a threshold value. The system includes an alcohol sensor operable to detect a current alcohol concentration in blood of the user, and a portable apparatus. The alcohol sensor and the portable apparatus comprises each a wireless communication apparatus. The wireless communication apparatus in the alcohol sensor is operable to wirelessly transmit the current alcohol concentration to the wireless communication apparatus in the portable apparatus.

Abstract: A calibration device for a breath alcohol testing device includes a pump providing a controlled air flow at a predetermined rate, a chamber in fluid communication with the pump that receives the air flow from the pump, and an outlet opening in fluid communication with the chamber that allows the air flow to exit the chamber in which the chamber and/or outlet opening can be heated to a predetermined maintainable temperature during operation of the pump. The calibration device is releasably connected to or brought in fluid communication with a breath alcohol testing device such that the air flow exiting the outlet opening passes into the testing device. The calibration device receives a sealed cartridge containing a predetermined alcohol concentration in the chamber and further includes a lid for opening/closing the chamber wherein the cartridge can be pierced such that the air flow provided by the pump to the chamber will pass through the cartridge.

Abstract: The present invention relates to a method and apparatus for measuring breath alcohol concentration of a user. A flow of an expired breath sample is passed through a fuel cell sensor giving an output signal proportional to the amount of alcohol present in the breath sample. By measuring the flow rate, the volume of the breath sample may be calculated, whereas the breath alcohol concentration is calculated based on the fuel cell output signal. Both the sample volume and the breath alcohol concentration values are continually updated by integrating the measured instantaneous flow rate and the fuel cell output signal over time. If the user stops blowing, flow compensation is performed to obtain a compensated fuel cell output signal using a stored calibration volume. Hence, an improved method for accurately measuring the breath alcohol concentration of a test person is achieved, capable of handling varied expired volumes of breath, which obviates the need for a sampling mechanism.