A device and process monitor a spatial area for a target gas. A sensor of the gas detection device used has a detection variable (ΔU.sub.korr,0) that is affected by the concentration of target gas. A detection variable sensor measures this detection variable (ΔU.sub.korr,0). The influence of a slower influencing variable and of a faster influencing variable, on the detection variable (ΔU.sub.korr,0), are computationally compensated to determine an influence-corrected detection variable (ΔU.sub.korr,1). Depending on the influence-corrected detection variable (ΔU.sub.korr,1), the target gas concentration is determined. For computational compensation, the time course (Dr[ΔU.sub.korr,0]) of the respective influence of the two influencing variables is estimated, for which a measurement value series from the detection variable sensor is used. The time course (Dr[ΔU.sub.korr,0]) is determined in such a way that the change per time unit of the influence lies within a given change tolerance band (Dr′[ΔU.sub.korr,0].sub.min, Dr′[ΔU.sub.korr,0].sub.max) for this influencing variable.

Systems and methods for measuring turbulent gas flux using high-speed vertical wind speed measurements (e.g., on the order of 5-10 Hz or more frequently) and low-speed gas content measurements (e.g., on the order of 5 Hz or less frequently), without the need for the sophisticated and expensive high-speed hardware to separate gas samples (e.g., into accumulation bags) according to updrafts and downdrafts. A time series of high-speed vertical wind speed data is used as a guide to distinguish between updrafts and downdrafts. When vertical wind speed is upward (updraft), the low-speed gas content is recorded into a data structure in one location, or marked with one flag. When vertical wind speed is downward (downdraft), the low-speed gas content is recorded into a different location, or marked with a different flag. Eddy Accumulation or Relaxed Eddy Accumulation computations can be performed using the stored gas content data to determine gas flux.

Systems and methods for analyzing a diffusion trend of a diffusible substance. The systems may obtain a plurality of sets of reference information relating to the diffusible substance from a plurality of devices respectively, each of the plurality of sets of reference information at least including a time point when a corresponding device detects the diffusible substance and a location where the device detects the diffusible substance. The plurality of sets of reference information may correspond to a same or a substantially same time domain. The systems may determine the diffusion trend of the diffusible substance based on the plurality of sets reference information.

Provided according to one embodiment of the present disclosure is a real-time odor tracking system using a vehicular odor measuring device, the system comprising: a vehicular odor measuring device which measures odor information while traveling on the ground; and a server which analyzes and manages information on odor generated from a specific point, on the basis of the odor information collected from the vehicular odor measuring device.

A concentration measurement method for measuring a concentration of impurities includes a step of irradiating a DUT 10 serving as a measurement target object with measurement light and stimulus light subjected to intensity modulation using a modulation signal including a default frequency, a step of outputting a detection signal by detecting an intensity of reflected light from the DUT 10 or transmitted light through the DUT 10, and a step of detecting a phase delay of the detection signal with respect to the modulation signal, obtaining a frequency at which the phase delay has a predetermined value, and estimating a concentration of impurities in the measurement target object on the basis of the frequency.

An apparatus for controlling a level of oxygen in a closed environment from an oxygen supply having an oxygen sensor for detecting the level of oxygen in the closed environment. The apparatus has a plurality of relays in communication with the sensor. The apparatus has a valve in communication with the relays and the oxygen supply which is automatically opened with the relays without human interaction, monitoring and adjustment to release oxygen from the oxygen supply into the environment when the level of oxygen in the environment goes below a first predetermined level and which is automatically closed with the relays without human interaction, monitoring and adjustment to stop oxygen from being released from the oxygen supply into the environment when the level of oxygen in the environment goes above a second predetermined level. A method for controlling a level of oxygen in a closed environment from an oxygen supply. A refuge chamber.

Systems and methods for measuring plant leaf gas exchange based on instantaneous mass balance in the sample chamber. The response of leaf net assimilation rate (A.sub.net) to computed leaf internal CO.sub.2 concentration (C.sub.1) is measured by continuously varying the input CO.sub.2 concentration and measuring the continuous difference between chamber input (reference) and output (sample) concentrations to compute a continuous series of A.sub.net values, which can then be plotted against computed C.sub.i. When combined with a similar response test using an empty chamber test to allow for sample chamber mixing and/or gas analyzer match dynamics and/or small flow-related residual time delays, such method provides accurate and rapid A C.sub.i response (RAC.sub.iR) curves in a much shorter time than conventional methods.

An information processing apparatus (2000) acquires time-series data (14) output by a sensor (10) and computes a plurality of feature constants θ.sub.i and a contribution value ξ.sub.i representing contribution with respect to the time-series data (14) for each feature constant θ.sub.i. Thereafter, the information processing apparatus (2000) outputs information in which a set Θ of the feature constants θ.sub.i and a set Ξ of the contribution values ξ.sub.i are associated with each other as a feature value of a target gas. As the feature constant θ, a velocity constant β or a time constant τ that is a reciprocal of the velocity constant can be adopted.

A Discrete Sample Introduction Module (DSIM) apparatus includes an internal tubing system to receive into the DSIM apparatus a discrete gas sample having a received concentration. A plurality of valves selectively partitions the internal tubing system to form a plurality of loops corresponding to a plurality of loop volumes to contain the discrete gas sample. The plurality of loop volumes receives a carrier gas to dilute the discrete gas sample to a plurality of preselected dilutions. The DSIM apparatus circulates a given one of the plurality of preselected dilutions for analysis by a spectrometer coupled to the DSIM apparatus.

Methods and apparatus allow for passive determination of a driver's Breath Alcohol Concentration (BrAC). Alcohol concentrations can be determined from exhaled breath, however inconvenience to a driver is often a barrier for incorporation of BrAC sensors into vehicles. The methods and apparatus allow for passive determination of a driver's BrAC, while detecting and accounting for a wide range of environmental conditions that may reduce the accuracy of a passive BrAC reading.