One variation of a method includes, during a test period: triggering release of a tracer test load into air in an environment, according to a set of release parameters, by a dispenser arranged within the environment, the first tracer test load comprising a first concentration of tracers of a first type in solution; and triggering an air sampler, located in the environment, to record a timeseries of aerosol data representing amounts of aerosol particles detected at the air sampler during the test period. The method further includes: deriving a tracer signal, representing changes in amounts of tracers in air detected at the air sampler during the test period, based on the timeseries of aerosol data and the set of release parameters; based on characteristics of the tracer signal, characterizing a set of aerosol flow metrics representing behavior of aerosols in the environment during the test period.

The instant disclosure provides a gas concentration detection device including a plurality of gas concentration measurement modules and a control module. The control module coupled with the plurality of gas concentration measurement modules. Each gas concentration measurement module including: a gas chamber, a signal generating unit and a sensing unit. The control module providing a plurality of clock signals, wherein each clock signal controls the corresponding signal generating unit to correspondingly generate the medium to enter the gas chamber and pass through the gas. The sensing unit outputs a sensing signal by receiving the medium, and the control module corrects the sensing signals from the sensing units to respectively obtain corrected sensing signals, and the corrected sensing signals are integrated by the control module to obtain a gas concentration signal.

A remote sensor calibration system remotely calibrates sensors of various types in an automated fashion. The remote sensor calibration system receives sensor output, associated with one or more locations and one or more times, from a sensor and its peer sensor population. The sensor output from the sensor and its peer sensor population is compared to generate a correction factor. The correction factor is transmitted to the sensor and used to calibrate the sensor. Communication will typically occur via one or more wireless links allowing the sensors to be remotely calibrate while maintaining their mobility.

A determination device determining malfunction of a humidity sensor includes a malfunction determination portion. The humidity sensor includes a humidity detector, a temperature detector and a heater. The humidity detector has a humidity-sensitive film in an intake passage and detects a relative humidity of intake air taken into an internal combustion engine for a vehicle. The temperature detector detects a temperature of the humidity-sensitive film. The heater heats the humidity-sensitive film and the temperature of the humidity-sensitive film is increased by the heater. The malfunction determination portion estimates an estimated relative humidity at a subsequent temperature from an original relative humidity and the subsequent temperature, and compares the estimated relative humidity at the subsequent temperature and an actual subsequent relative humidity to determine malfunction of the humidity detector.

A method for calibrating an exhaust gas sensor arranged in a measurement chamber, includes providing a measurement chamber in or adjacent to an exhaust channel of an internal combustion engine. At the start of a calibration phase, exhaust gas present in the measurement chamber is displaced by a filling of the measurement chamber with calibration gas, and at the end of the calibration phase, exhaust gas diffuses into and/or is introduced into the measurement chamber.

An apparatus for optical in-situ gas analysis includes: a housing; a measuring lance a first end connected to the housing and a second end projecting into the gas to be measured; a light transmitter that is arranged in the housing and whose light is conducted into the measuring lance and is reflected by a reflector arranged at the second end onto a light receiver, and the optical path defines an optical measurement path within the measuring lance; and, an evaluation device for evaluating received light signals of the light receiver. In order to be able to reduce the consumption of test gas, the measuring lance has an outer tube, with the outer tube having openings for the gas to be measured. The openings can be closed by at least one seal for the test phase, with the seal searingly closing the openings by the enlargement of its volume.

A nitrogen oxide based gas sensor includes: a substrate provided with a beam structure having a MEMS structure; a heater disposed on the substrate; a lower electrode disposed on the heater, a solid electrolyte layer disposed on the lower electrode; an upper electrode disposed on a surface of the solid electrolyte layer facing the lower electrode and configured to introduce a measurement target gas; a cavity portion formed in the substrate; and a gas flow path disposed so as to connect the cavity portion and the lower electrode, wherein the gas sensor is configured to detect a concentration of nitrogen oxide in the measurement target gas.

A combustion analyzer configured to simultaneously detect the concentrations of oxygen, carbon monoxide and methane in a combustion process is provided. The combustion analyzer includes an oxygen sensor configured to detect the oxygen in the combustion process and generate a first sensor signal indicative of the concentration of oxygen in the combustion process. The combustion analyzer further includes a dual carbon monoxide-methane sensor configured to operate at approximately 600° C. and provide a second sensor signal indicative of methane concentration and at approximately 300° C. to selectively provide a third sensor signal indicative of carbon monoxide concentration. The combustion analyzer finally includes a controller configured to receive the sensor signals, determine the concentration of oxygen and generate a carbon monoxide concentration output and a methane concentration output based on the dual carbon monoxide-methane sensor signals and the concentration of oxygen.

A gas routing element (20) for gassing at least one gas-measuring device (90.1-90.x), whereby each gas-measuring device (90.x-90.x) can be arranged in a test module (30.1-30.x) of a calibrating station (100). The gas-measuring devices (90.1-90.x) have a first gas inlet opening (1.1-1.x), a communicating feed duct (2.1-2.x) and a communicating first gas outlet openings (3.1-3.x, 13.1-13.x). Second gas inlet openings (4.1-4.x, 14.1-14.x) are connected to a communicating recirculating duct (5.1-5.x) and a second gas outlet opening (6.1-6.x) is connected with the recirculating duct (5.1-5.x) in a gas-communicating manner. A fastening device (70) fastens the gas routing element (20) to the calibrating station (100) or to a test module (30.1-30.x) of the calibrating station (100). A calibrating station (100) is also provided for the gas-measuring devices (90.1-90.x) with such a gas routing element (20).

A wet standard calibration system which utilizes a heat conducting foam with the liquid therein to serve as a primary heating device to avoid the need to include mechanical agitation. The system is particularly useful for generating a vapor comprising water and ethanol which can be used for the calibration of breath alcohol testers.