Abstract: A timing device for keeping time by marking the time boundaries between contiguous time periods. Time is measured by measuring charging voltage on a pair of capacitances where each capacitance is charged and discharge in successive cycles. Detection of a preset value of potential on each one of the capacitances is used to initiate commencement of charge on the other capacitance and detection of another preset value on the other capacitor is used to record measurement of potential at a full scale potential point on the one capacitor. By this means “dynamic” measurements of potential are made by which is meant that the potentials are measured while the potential is changing, rather than when the potential has reached a target end point. This technique eliminates errors arising from unstable conditions at the capacitor due to, for example, dielectric hysteresis, a requirement to measure a charging or discharging step simultaneous with a measuring step, etc.

Abstract: A timing device for keeping time by marking the time boundaries between contiguous time periods. Time is measured by measuring charging voltage on a pair of capacitances where each capacitance is charged and discharge in successive cycles. Detection of a preset value of potential on each one of the capacitances is used to initiate commencement of charge on the other capacitance and detection of another preset value on the other capacitor is used to record measurement of potential at a full scale potentail point on the one capacitor. By this means “dynamic” measurements of potential are made by which is meant that the potentials are measured while the potential is changing and rather than when the potential has reached a target end point. This technique eliminates errors arising from unstable conditions at the capacitor due to, for example, dielectric hysteresis, a requirement to measure a charging or discharging step simultaneous with a measuring step, etc.

Abstract: Disclosed is a system both apparatus and method, for analyzing a breath sample (22). A transducer (24) senses the pressure, temperature and humidity of the breath sample and in response generates a breath signature signal (26). A sensor (28) detects the alcohol content of the breath sample and in response generates an alcohol signal (30). Also included is a breath reference (32), and an alcohol reference (34) which includes an alcohol threshold level (36). A first comparator (38) compares the breath signature signal with the breath reference, and in response generates either a valid signal (40) if the signals substantially match or an invalid signal (44) if the signals do not substantially match. A second comparator compares the alcohol signal with the alcohol reference, and in response generates either a passing signal or a failing signal depending on whether or not the threshold level is exceeded.

Abstract: Disclosed is a system, both apparatus and method, for analyzing a breath sample (22). A transducer (24) senses the pressure, temperature and humidity of the breath sample and in response generates a breath signature signal (26). A sensor (28) detects the alcohol content of the breath sample and in response generates an alcohol signal (30). Also included is a breath reference (32), and an alcohol reference (34) which includes an alcohol threshold level (36). A first comparator (38) compares the breath signature signal with the breath reference, and in response generates either a valid signal (40) if the signals substantially match or an invalid signal (44) if the signals do not substantially match. A second comparator compares the alcohol signal with the alcohol reference, and in response generates either a passing signal or a failing signal depending on whether or not the threshold level is exceeded.