Abstract: A method for determining the gas content of a person's breathing air, comprises, first determining when the breathing air is at a condition in which best testing results will be effected. This is done by arranging a capacitor in a breathing tube through which the breathing air is directed. The capacitor is first heated to a predetermined temperature and the breathing air is directed over it so as to cool it until it has attained a predetermined temperature change. This temperature change is such that it will take place when the person's breathing air has its desired constituency. When this occurs, the breathing air is then directed into a test chamber in which it is tested to determine the constituency of the breathing air particularly the percentage of alcohol which it contains.

Abstract: A method and apparatus of determining the alcohol content of the breath of a test person comprising, measuring the alcohol content of the breath to produce an alcohol content signal, measuring the change in the alcohol content signal, measuring a flow of the breath of the test person, and indicating the alcohol content using the alcohol content signal only when the change in the signal per unit time is below a preselected change value and the flow is above a preselected flow value and where the flow has not dropped below the predetermined flow value since it first reached the predetermined flow value. The change in the signal is determined by the change in the signal per unit time, times the inverse of the instantaneous value for the signal. When the change in the signal satisfies the requirement, a control signal is fed to an AND gate.

Abstract: A device and method for determining the alcohol content of a test person's breath comprising, a breathing sample line adapted to receive the test person's breath, a valve in the sample line for closing a flow of breath therein, a test chamber connected to the sample line downstream of the valve for receiving and testing the breath and a pressure sensing transducer connected to the sample line upstream of the valve for sensing the attainment of a predetermined pressure in the sample line. A clock is connected to the pressure sensing transducer and begins to operate when the preselected pressure has been obtained. The clock is connected to the valve and opens the valve only after the expiration of a preselected time period where the preselected pressure has been maintained throughout the period.

Abstract: An apparatus for the controlled proportioning of gases to be delivered to a consumer comprises a mixed gas line containing the mixed gases to be delivered to the consumer which is connected to a plurality of separate gas supply lines. Each of the supply lines includes a quick-acting, electrically controlled valve which is controlled by control means which is effective to deliver a control pulse to open and close the valve in accordance with a set time slot pattern. For this purpose, the controller advantageously includes means for sensing the pressure in each of the supply lines and the mixed gas line and for regulating the quick-acting valves in accordance with one or more input signals which are fed to a computer section of a controller which has an actuator section which is operated in accordance with the sensed information and the input signals to carry out the supply of the gases in the set time slot pattern.

Abstract: Device for determining variations within an indicator tube having a material which varies in light intensity or color in the presence of particular gases, comprises a first set of light barrier devices as light sources and photoelectric cells on respective sides of the tube. A reference set of light barrier means is provided for sensing a reference value of light through the tube and is connected to a comparator for sensing the variations between it and the first set of light barrier tubes and for recording this information on a counter. The counters are connected to a time signal transmitter and time signal receiver and the predetermined variations which occur at various time intervals are picked up by an indicator or alarm circuit designed to show the variations and indications which are sensed in a particular time period.

Abstract: A method for determining the alcohol content in the exhaling respiratory air using an alcohol measuring instrument and measuring the alcohol content when the exhaling air transmits the determined value of the alcohol concentration. This determined value of alcohol concentration occurs when the time variation related to the height of the alcohol signal is below a predetermined threshold value and the velocity of flow of the exhaling air is above a given value and is maintained without interruption for a given time. The apparatus includes an infrared measuring instrument which is connected into the respiratory air current and measures the alcohol concentration of the exhaling air. This value is applied to an indicator through a linear gate when an AND-gate is triggered by threshold comparators and a timing element activated by a threshold comparator.