An apparatus for automatic leak detection includes a fixture having a primary seal and a secondary seal. The fixture connects to a workpiece to enclose a test volume defined in the workpiece. The seals are to interface with the workpiece to at least partially enclose a buffer volume. An enclosure is to connect to the fixture to enclose a test portion of the workpiece to form a test chamber. The secondary seal separates the buffer volume from the test chamber. The test volume and the test chamber have a tracer gas pressure differential between them. A port in fluid communication with the buffer volume removes fixture leakage from the buffer volume. A detector detects the tracer gas in the test volume or the test chamber where the tracer gas pressure differential between the test volume and the test chamber urges workpiece leakage of the tracer gas to accumulate.

Various embodiments described herein relate to methods, apparatuses, and systems for recovering gas sensors from silicone poisoning. In an example embodiment, a method of recovering a gas sensing apparatus from silicone poisoning is provided. The method includes exposing the gas sensing apparatus to a predetermined hydrogen concentration for a period of hydrogen exposure time. The predetermined hydrogen concentration breaks down the silicon oxide bonds formed on a catalytic bead of the gas sensing apparatus. The method also includes providing a methane concentration to the gas sensing apparatus for a period of methane exposure time. The method further includes determining that the gas sensing apparatus satisfies a predetermined calibration sensitivity based on the reaction of the gas sensing apparatus to the methane concentration.

A gas sensor includes a gas detecting element that includes a first electrode, a metal oxide layer, and a second electrode; and a first insulating film that has an opening allowing the second electrode to be partially exposed therethrough and covers the first electrode, the metal oxide layer, and another part of the second electrode. The metal oxide layer has a characteristic where its resistance value changes as the second electrode makes contact with gas molecules including hydrogen atoms. A first step is provided at a portion lying on an interface between the metal oxide layer and the second electrode and located within the opening as viewed in plan view. A local region is provided in the metal oxide layer and near the first step. A degree of oxygen deficiency of the local region is greater than a degree of oxygen deficiency of other regions in the metal oxide layer.

A hazardous gas monitoring system is provided. The hazardous gas monitoring system includes a panel including multiple sensing lines. Each sensing line is configured to receive and monitor an air sample. Each sensing line includes a water separator to remove condensed moisture, a coalescing filter disposed downstream of the water separator, and a flow and gas monitoring system disposed downstream of the coalescing filter. The hazardous gas monitoring system may be used to monitor the presence of hazardous gases within an enclosure, such as an enclosure for a turbomachine.

A composition analysis apparatus for analyzing a composition of a gas includes: a first measurement part measuring concentrations of gases included in a gas to be analyzed; a part calculating converted calorific values, the part including a second measurement part measuring a refractive index of the gas and a speed of a sound propagating through the gas and calculating a converted calorific value of the gas for the refractive index and the sound speed; a part calculating a base miscellaneous gas total error calorific value, the part calculating, based on the converted calorific values, a base error calorific value of an error calorific value attributable to miscellaneous gases included in the gas; and a part calculating a concentration of a first gas not to be measured, the part calculating the concentration of the first gas based on the concentrations of the measured gases and the base error calorific value.

A notification system for notifying detection of vaping, smoking, or potential bullying at a premises includes a plurality of sensors, each being configured to sense air quality, sound, and temperature at the premises, a memory configured to store a responsibility schedule, and positional information and base data for each of the plurality of sensors, a controller configured to determine detection of vaping, smoking, or potential bullying by comparing results sensed by the plurality of sensors with the base data, and a message server configured to send an alert to a person based on the responsibility schedule, a detection location, and a detection time. The person is responsible at the detection location and at the detection time based on the responsibility schedule.

It is proposed a sensor for measuring a gas property, wherein the sensor comprises a semiconductor die, wherein the semiconductor die comprises a reference cavity and a measuring cavity, wherein a reference sensor element is arranged in the reference cavity, wherein a measuring sensor element is arranged in the measuring cavity, wherein the reference cavity is sealed from ambient gas, wherein the measuring cavity is fluidly connected to ambient gas. Further it is proposed a method for manufacturing such a sensor.

A system and method of determining a target gas concentrations in a fluid environment using a gas sensor that improves the efficiency and accuracy of the gas sensor's measurements by taking measurements of electrical characteristics of the gas sensor at different temperatures, taking measurements during a transition between a first temperature and a second temperature, taking more frequent measurements, detecting when the gas sensor has reached equilibrium, using multiple sensors, accounting for offsets and drifts, reducing the time the sensor is not live, using various algorithms, or any combination thereof.

A catalyst for a gas sensor includes a support and a core-shell type complex contained in the support. The complex includes a metal-containing core and a porous nanostructured shell. A contact combustion type gas sensor includes the catalyst.

An illustrative example hydrogen concentration sensor includes a plurality of electrically conductive plates. A hydrogen evolving electrode assembly in a first location between two of the plates is configured to generate hydrogen. A detection electrode assembly in a second location between two of the plates is configured to provide an indication of a concentration of hydrogen in a fluid of interest. A plurality of isolating layers includes a first isolating layer at the first location between two of the plates and a second isolating layer at the second location between two of the plates. The first and second isolating layers each include a sealant that secures the two plates together and seals a perimeter around the electrode assembly at the corresponding location.