Abstract: Method for adapting the concentration of a sample gas in a gas mixture to be analysed by a gas chromatograph assembly (10), the gas chromatograph assembly (10) comprising a sample gas inlet (20) for introducing a sample gas to be analysed, a secondary gas inlet (40), a gas chromatograph infrared sensor (12), a gas chromatograph column (26), and a gas chromatograph bypass (28) parallel to the column (26), characterized by a) introducing an amount of sample gas through the sample gas inlet (20), b) introducing an amount of secondary gas through the secondary gas inlet (40), c) mixing the sample gas and the secondary gas to a gas mixture and conducting the gas mixture via the gas chromatograph bypass (28), d) circulating the gas mixture in a gas conducting loop (52) comprising the gas chromatograph bypass (28), the gas chromatograph infrared sensor (12) and not comprising the gas chromatograph column (26), e) analysing the gas mixture thus obtained by means of gas chromatography employing the gas chromatograp

Abstract: A vacuum bell probe for detecting leaks in underground gas pipes may include a flexible suction cup having a bottom side forming a suction opening. The suction cup may define an interior volume. The bottom side may include a soft seal ring having a higher elasticity than the suction cup, surrounding the suction opening and forming a contact surface adapted to create a seal in contact with a ground surface under which a gas leak may be assumed such that a vacuum may be generated within the interior volume upon contact to the ground surface.

Abstract: Method for wide range gas detection using a gas detection system comprising a sample gas inlet, a reference gas inlet, a gas modulation valve and a gas analyzer, wherein the gas modulation valve alternatingly connects the sample gas inlet to the gas analyzer during a sample gas time period and the reference gas inlet to the gas analyzer during a reference gas time period, characterized in that the sample gas time period is shorter than the reference gas time period such that the sample gas concentration in the gas analyzer is reduced.

Abstract: A vacuum bell probe for detecting leaks in underground gas pipes may include a flexible suction cup having a bottom side forming a suction opening. The suction cup may define an interior volume. The bottom side may include a soft seal ring having a higher elasticity than the suction cup, surrounding the suction opening and forming a contact surface adapted to create a seal in contact with a ground surface under which a gas leak may be assumed such that a vacuum may be generated within the interior volume upon contact to the ground surface.

Abstract: Described is a method for quantifying the amount of optically interfering gas impurities in a gas detection system comprising a sample gas inlet, a reference gas inlet, a gas modulation valve, and an infrared absorption gas detector used for analysis of methane or natural gas, wherein the gas modulation valve alternatingly connects the sample gas inlet to the gas detector during a sample gas time period and the reference gas inlet to the gas detector during a reference gas time period. The method includes measuring an infrared absorption for at least two different sample gas concentrations in the gas detector achieved via respective different ratios from the sample gas time period and the reference gas time period, and comparing amplitudes of different measurement signals of the at least two different sample gas concentrations with calibration functions to assess an actual gas impurity concentration in the sampled gas.

Abstract: A gas detection system, comprising a sample gas inlet, a reference gas inlet and a gas modulation valve alternatingly connecting one of the sample gas inlet and the reference gas inlet to a gas sensor, is characterized in that a selective transfer filter is located in the gas flow path connecting the gas modulation valve and the gas sensor.

Abstract: Method for determining whether a gas sample originates from biological processes or from a gas installation being tested and containing a utility gas is characterized in that an increased concentration of hydrogen in the sample as compared to that present in the utility gas is used as evidence that the sample originates from biological decay processes and not from the gas installation under test.

Abstract: Infrared gas detection system comprising a gas inlet, an infrared gas analyzer connected to the gas inlet and a secondary gas sensor connected to the gas inlet, and an evaluation device evaluating the measurement signals from both the infrared gas analyzer and from the secondary gas sensor, such that a gas is identified only if both the infrared measurement signal and the secondary measurement signal coincide in time.

Abstract: Described is a method for quantifying the amount of optically interfering gas impurities in a gas detection system comprising a sample gas inlet, a reference gas inlet, a gas modulation valve, and an infrared absorption gas detector used for analysis of methane or natural gas, wherein the gas modulation valve alternatingly connects the sample gas inlet to the gas detector during a sample gas time period and the reference gas inlet to the gas detector during a reference gas time period. The method includes measuring an infrared absorption for at least two different sample gas concentrations in the gas detector achieved via respective different ratios from the sample gas time period and the reference gas time period, and comparing amplitudes of different measurement signals of the at least two different sample gas concentrations with calibration functions to assess an actual gas impurity concentration in the sampled gas.

Abstract: Method for wide range gas detection using a gas detection system comprising a sample gas inlet, a reference gas inlet, a gas modulation valve and a gas analyzer, wherein the gas modulation valve alternatingly connects the sample gas inlet to the gas analyzer during a sample gas time period and the reference gas inlet to the gas analyzer during a reference gas time period, characterized in that the sample gas time period is shorter than the reference gas time period such that the sample gas concentration in the gas analyzer is reduced.

Abstract: Infrared gas detection system comprising a gas inlet, an infrared gas analyzer connected to the gas inlet and a secondary gas sensor connected to the gas inlet, and an evaluation device evaluating the measurement signals from both the infrared gas analyzer and from the secondary gas sensor, such that a gas is identified only if both the infrared measurement signal and the secondary measurement signal coincide in time.

Abstract: A gas detection system, comprising a sample gas inlet, a reference gas inlet and a gas modulation valve alternatingly connecting one of the sample gas inlet and the reference gas inlet to a gas sensor, is characterized in that a selective transfer filter is located in the gas flow path connecting the gas modulation valve and the gas sensor.

Abstract: Method for determining whether a gas sample originates from biological processes or from a gas installation being tested and containing a utility gas is characterized in that an increased concentration of hydrogen in the sample as compared to that present in the utility gas is used as evidence that the sample originates from biological decay processes and not from the gas installation under test.

Abstract: A method for detecting the location of a gas leak 22 in buried utility gas pipes 12 by measuring the presence of a gas 18 below or above the ground surface 14 above the pipe 12 is improved by injecting a tracer gas 18 which is lighter than air into the utility gas 26 within the pipe 12 and by using a gas detector 28 having a higher sensitivity to the tracer gas 18 than to the utility gas 26 for pin-pointing the leak position 22.

Abstract: The present invention relates to gas sensor housing (1), comprising: a gas sensor (3) held by a housing body (11) below a primary gas permeable membrane (2); at least one connector element (10) molded into the housing body (11) such that the respective ends thereof enable connectivity to the gas sensor (3) such that signals may be carried from the gas sensor (3) to the connector element (10); a sensor envelope (9) providing an enclosure for the housing body (11); means for retaining the primary gas permeable membrane (2) in place above the gas sensor (3); a spacer section (7) providing a separation distance (X) between the gas sensor (3) and the primary gas permeable membrane (2).

Abstract: A system for detection of a leak at a leakage testing point of a test object by a tracer gas. A positionable tracer gas mediating unit has a tip. A marker is attachable at the leakage testing point. A marker detector is associated with the positionable tracer gas mediating unit. The tip of the tracer gas mediating unit is arranged to be positioned within a predetermined distance interval from the marker during a leak detection test. The marker detector is arranged to detect the marker when the tip is positioned within the predetermined distance interval so as to certify a correct positioning of the tip.

Abstract: A gas probe for sampling gas molecules from a fluid. A housing includes an orifice and is adapted to be arranged in gas communication with a test gas sensor. The probe includes a stack of layers, whereby gas sample molecules have to pass through all layers of the stack in order reach the sensor. The stack includes at least a first membrane layer, a first spacer layer, a first filter layer and a second spacer layer. The housing includes an inlet for introducing blocking gas molecules into the second spacer layer and an outlet for discharging blocking gas molecules out of the first spacer layer. The gas probe is connectable to a control unit for controlling the blocking gas flow into the second spacer layer.

Abstract: The present invention relates to gas sensor housing (1), comprising: a gas sensor (3) held by a housing body (11) below a primary gas permeable membrane (2); at least one connector element (10) moulded into the housing body (11) such that the respective ends thereof enable connectivity to the gas sensor (3) such that signals may be carried from the gas sensor (3) to the connector element (10); a sensor envelope (9) providing an enclosure for the housing body (11); means for retaining the primary gas permeable membrane (2) in place above the gas sensor (3); a spacer section (7) providing a separation distance (X) between the gas sensor (3) and the primary gas permeable membrane (2).

Abstract: A gas probe for sampling gas molecules from a fluid. A housing includes an orifice and is adapted to be arranged in gas communication with a test gas sensor. The probe includes a stack of layers, whereby gas sample molecules have to pass through all layers of the stack in order reach the sensor. The stack includes at least a first membrane layer, a first spacer layer, a first filter layer and a second spacer layer. The housing includes an inlet for introducing blocking gas molecules into the second spacer layer and an outlet for discharging blocking gas molecules out of the first spacer layer. The gas probe is connectable to a control unit for controlling the blocking gas flow into the second spacer layer.

Abstract: A system for detection of a leak at a leakage testing point of a test object by a tracer gas. A positionable tracer gas mediating unit has a tip. A marker is attachable at the leakage testing point. A marker detector is associated with the positionable tracer gas mediating unit. The tip of the tracer gas mediating unit is arranged to be positioned within a predetermined distance interval from the marker during a leak detection test. The marker detector is arranged to detect the marker when the tip is positioned within the predetermined distance interval so as to certify a correct positioning of the tip.