Abstract: An apparatus is provided for the analysis of flammable vapors in an industrial application, such as a solvent drying operation or the like. The apparatus continuously withdraws and returns a sample of gas from the process, separates the sample into a primary portion and a secondary test portion, tests the flammability of the test portion and recombines the test portion with the primary sample, which has been restricted to create a pressure differential enabling the flow of the test portion through the testing procedure.

Abstract: A method of discriminating alcohols different from ethanol in breath samples includes sampling voltages from a fuel cell at a rapid rate to establish a curve rising, upon introduction of a sample containing a known amount of ethanol without interferants, from an initial base line to a peak; determining a peak voltage; establishing an end point; determining the area under the curve from the introduction of the sample to the end point, and determing at least two other areas under the curve between the peak and the end point, a peak area, between the peak and a point on the curve relatively near the peak, and a trail area, between the end point and a point nearer the end point than the peak area; introducing to the fuel cell a breath sample that may contain an interferant in the form of an alcohol different from ethanol, and determining the peak voltage, end point, total area, peak area and trail area using the same criteria as were used in determining those pieces of information in connection with the sample co

Abstract: A hydrogen gas analyzer having an improved delivery system is provided wherein a plurality of branched passageways can supply a sample cell and an additive fuel to a combustion chamber. Cutoff valves can be activated to control the flow rates through the respective passageways so that when the concentration of hydrogen in the sample gas is high, the flow rate from the additive fuel will be reduced, and when the concentration of hydrogen is low, the flow rate of the sample gas is reduced.

Abstract: Atmospheric concentrations of reducing gases are measured and indicated by a gas sensor whose conductivity varies in accordance with variations in the concentration of ambient reducing gases, a resistance in series with the gas sensor for establishing a reference voltage, a circuit interconnecting the resistance with a linearizing circuit including the non-inverting inputs of a plurality of voltage comparators and with the inverting input of a fault detecting comparator, an adjustable resistance of a magnitude substantially equal to the response of the sensor at its maximum value, a thermistor in parallel with a fixed resistance and in series with the adjustable resistance and with a voltage divider including a plurality of fixed resistors respectively connected with the inverting inputs of the plurality of voltage comparators together with a light emitting diode in series with the output of each voltage comparator, each light emitting diode indicating a concentration of an ambient reducing gas in terms of pa

Abstract: A method to detect, measure or remove trace amounts of condensible vapors in compressed gases. The concentration of droplets detected, measured or removed may be as low as part per trillion. The compressed gas comprising a carrier gas and condensible vapors is discharged through a critical orifice in order to condense the vapors in the form of homogeneous droplets. The droplets are either detected, or their concentration measured or removed from the expanded carrier gas.

Abstract: Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising (a) a mechanochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, operatively coupled to (b) a transducer capable of directly converting said expansion or contraction to a measurable electrical response.

Abstract: In a gas detection system for detecting the content of inflammable, explosive and/or toxic or other gases an arrangement is proposed according to which a central electronic evaluation system is connected to a plurality of measuring heads, which are installed at the points of measurement, by a single common two-wire line and each measuring head is provided, at its place of installation, with its own intelligence (microprocessor) for processing at least partly the values supplied by the sensor, each measuring head being equipped with at least two sensors of different types or measuring ranges and with an additional temperature sensor and each sensor having an identification which is indicative of the type and measuring range of the sensor and which is picked up by the measuring head.

Abstract: A sample analyzer to detect elements in a gaseous residue generated in an extraction furnace. The sample analyzer introduces the gaseous residue into a detector to be analyzed. The sample analyzer employs a buffer vessel having a variable internal capacity disposed between the extraction furnace and the detector. The variable capacity buffer vessel provides the capability to accurately analyze samples having wide variations in the concentration of substances to be analyzed.

Abstract: A vehicular ignition interlock system having a flow rate integrator and a servograph. The integrator is provided to insure that only "deep lung air" is analyzed for alcohol. A pressure transducer is employed in the integrator such that the output of the transducer is proportional to the air flow rate. As the rate of flow of a breath sample varies, a corresponding change in the required duration of the breath sample is made to insure that a deep lung air sample is being analyzed. The servograph comprises a plurality of colored lights and a tone generator which are controlled by a computer to direct the operator to adjust the rate of flow of his or her breath sample in accordance with the visual indication provided by the lights. Thus the servograph and the flow rate integrator insure that only a human subject will be capable of providing the air sample to be analyzed. A gas sensor and flow sensor are mounted in a replaceable module to facilitate field repair, replacement and calibration.

Abstract: The amount of carbon monoxide or oxygen in a gas is measured by determining the change in dielectric properties of a polymer film disposed between two electrodes. A preferred polymer film comprises an organometallic gas carrier interdispersed within an interpenetrating polymer network matrix.

Abstract: A gas sampling device including a chamber assembly formed of a chamber base having a chamber top mounted thereto is disclosed. A gas sensor is mounted to the chamber base in fluid communication with a gas flow passage therethrough. A motor is mounted to the lower surface of the chamber base and has a shaft extending through the chamber base. A fan is mounted onto the motor shaft within the chamber housing. An inlet flow passage extends through the chamber top above the center of the fan and an outlet flow passage extends through the chamber top above the gas flow passage. The fan and the chamber top are provided with a particular configuration to provide for efficient and smooth flows of gas through the housing and to the sensor.

Abstract: A detector system (10) especially suited for detecting a halogen containing component in a gas stream includes a gas chromatograph (12), which is connected by gas line (13) to pyrolysis chamber (14). Sources (16) of additional gas streams are connected by a gas line (18) to the pyrolysis chamber (14). The detector electrodes in the pyrolysis chamber (14) are electrically connected to detector electronics (20) by line (22). A temperature control circuit (24) is electrically connected to heater (26) by line (28). Heater (26) is thermally coupled to the pyrolysis chamber (b 14) at (30). The pyrolysis chamber (14) is thermally coupled to thermocouple (32) at (34). The thermocouple (32) is electrically connected to the temperature control circuit (24) by line (36). The heater (26) is independent of the detector electrodes and maintains a temperature between about 700 degrees and 1000 degrees Centigrade. The detector electrodes are substantially alkali metal free.

Abstract: Disclosed is an oxygen sensor of the resistive type for the measurement of relative fluid concentrations of fluid reactive species. The following are disposed on one and the same substrate:a sensitive element, the resistivity of which is sensitive to an excess of one of the reactive species;a thermistor mounted as a resistance bridge with the sensitive element;a heating resistor fixing the minimum temperature threshold of operation.Application: The disclosed device can be applied notably to oxygen sensors.

Abstract: The invention relates to a method for analyzing a gas mixture which contains a dust-like solid by separating and directing to analysis a certain quantity of the gas mixture along a sample-taking conduit, wherein a known quantity of liquid is mixed with the separated gas mixture in order to absorb the gas mixture into the liquid. The analysis is performed by analyzing the liquid which has absorbed the gas mixture. The liquid is mixed with the separated gas mixture which is being directed to analysis immediately after the gas mixture has been separated, and the separated gas mixture and the liquid are directed together along the sample-taking conduit to analysis.

Abstract: A device for the transport of a gas sample into the measuring chamber of a detector for the determination of the portion of a component in a gas, and in particular of alcohol in respiratory air, includes a piston-cylinder unit serves as the transport element. The sample is used as completely as possible for the signal analysis of the sensor at the beginning of the sampling process. The measuring-sensitive surface of the sensor comprises a part of the wall of the cylinder chamber of the transport unit which serves as the measuring chamber. The path on which the sample is guided between the inlet and the cylinder chamber is defined by a deviation baffle provided along the measuring-sensitive surface of the sensor.

Abstract: A method for analyzing a gas by means of microwave absorption including the steps of: generating a microwave at at least one frequency; continuously sweeping the microwave frequency over the absorption frequency of a known pure gas component; transmitting the microwave frequency to a measuring cell containing the gas to be measured and to a reference cell containing the known pure gas component; detecting an absorption measurement signal from the measuring cell; detecting an absorption reference signal from the reference cell; integrating the intensity of the measurement signal; and applying an alternating Stark voltage with a phase shift to the measuring cell and to the reference cell. Also provided is an apparatus which may be used in conjunction with this method.

Abstract: A portal vapor detection system for sampling air proximal to the bodies of individuals in which air sampling tubes positioned within movable panels convey a gas flow into an analyzing system. Low vapor pressure materials such as plastic explosives or illicit drugs carried by individuals can be detected thereby enabling the prevention of their transport into aircraft or secured areas.

Abstract: An improved oxygen analyzer device is disclosed which comprises a gas flow passage having inlet and exhaust ports, an oxygen concentration detector in proximity to the exhaust port and first and second parallel intermediate flow passages, one of which contains a purifier to remove oxygen from the gas flowing therethrough. The device is characterized by the use of metal, diaphram-type, three-way valves in the branch-off and junction points between the intermediate flow passages. The valves eliminate dead space in conventional devices that extends both the calibration and analysis time of such devices.

Abstract: When the output of a gas sensor is approximately constant, the sensor output is stored as a reference output. Evolution of a gas is detected from variations in the sensor output from the stored reference output. The sensor output which is constant is detected by establishing that the difference between a maximum and a minimum of sensor output in a predetermined section is not greater than a specified value.

Abstract: A method and apparatus for the measurement of the properties of fuel gases dependent upon flow and pressure, and more particularly upon the dyanmic viscosity and/or the density of the fuel gases. The apparatus includes a device to control the flow of the fuel gas and at least one flow restrictor in the gasway. The design and the operation of such an apparatus is simplified by the integration of a gas holding device having a capacity which changes in response to the pressure difference between the pressure inside the inner chamber of the device and the ambient pressure. An aneroid capsule element in a line connecting a closeable gas inlet and at least one flow restrictor may be used for this purpose. A time measurement device may be switched on and off as a function of predetermined capacities of the gas holding device.

Abstract: A control system has a controlled element, such as an element for sensing an air/fuel ratio of an internal combustion engine, having a high order lag, a controller element connected with the controlled element to form a closed path, and a third element connected with the controlled element and controller element for modifying an output signal of the controlled element in accordance with an output signal of the controller element so that a phase angle in a frequency response of a loop transfer function of the controlled and controller elements does not reach -180.degree..

Abstract: A precision gas metering apparatus is disclosed and comprises facing duplicate cylinders each having a piston therein, wherein the two cylinders are aligned with one another so that a common non-rotating shaft moves pistons in each. The shaft is driven by a stepping motor having a traveling nut connected to said shaft to impart rotation from the motor which is converted into linear movement of the shaft. With suitable valves and a pressure transducer, gas to be measured is delivered first to one volume and then to the other, the pistons being driven to equalize in flowing gas pressure to atmospheric pressure level, and thereafter summing the total volumetric filling by summing each filling of each chamber, and also summing any partial fillings. A pressure transducer assures that the filled chambers are held to a specified volume.

Abstract: There is disclosed a fluid meter incorporating a bi-stable resilient member positioned in a housing. Fluid flow into and out of the housing causes the bi-stable member to oscillate in a single oscillatory mode. Since each oscillation of the member is proportional to fluid flow into and out of the housing, a mechanism is provided to count the number of oscillations to provide an indication of fluid flow.

Abstract: System for measuring the volume value of a confined space, in particular the functional residual capacity of the lungs of a patient, by means of a measuring space having a variable volume and a gas analyzer, which measuring space can be connected to the confined space and is provided with means for supplying and removing air, as well as for supplying oxygen and a detectable gas, the gas analyzer generating an output signal which is a linear function of the concentration of this detectable gas and the zero level of which is adjustable.