A system includes an array of chemical, pressure, and temperature sensors, and a temporal airflow modulator configured to provide sniffed vapors in a temporally-modulated sequence through a plurality of different air paths across multiple sensor locations.

Disclosed are methods for measuring building health index using some mandatory and set of optionally configured parameters and utilizing building monitoring system having a connection to sensors in or pertaining to a building, and including central computing environment and one or more display devices showing the measurement. A building utilizing this method may be installed with one or more sensors, and which may be communicating to a locally installed communication device or a centrally installed computing environment that can collect the measurements over a period.

Computer systems, methods, and apparatuses for estimating changes in gas emissions are described. A computer system may monitor overall emission levels based on sensor outputs from a plurality of gas sensors in a facility. The computer system may estimate a total emission level over a time interval based on the accumulative, gas-response-factor weighted detections of the gas sensors. Emissions from maintenance activities may be excluded as appropriate. The total emission level may be compared with total emission level estimated from different time intervals and/or different facilities. The computer system may be further used for comparing emissions across multiple facilities, or emissions from facilities across multiple regions.

Airborne contaminant detection and localization systems include an HVAC system having a duct, a first vent connected to a first indoor space, and a second vent fluidly connected to a second indoor space, with the second vent being downstream from the first vent in a flow direction along the duct. A monitoring system includes a first and second sensor elements arranged proximate the first and second vents, respectively, the sensor elements configured to detect one or more airborne contaminants. A central unit receives sensor data from the sensor elements. The central unit includes information regarding a location of each of the sensor elements within the duct. The central unit determines the presence and intensity of an airborne contaminant in the duct from the sensor data and establishes a detection zone that includes a portion of the vent having a highest detected intensity of the airborne contaminant.

Multiple low cost individual sensors communicate with a server. A proxy sensor communicates with the server. The server periodically compares information from the individual sensors with information from the proxy sensor. The server validates and accepts information from individual sensors. The server changes gain and offset values for individual sensors providing information that is not validated by the comparing.

A portable electronic device for use in different orientations includes a signal control module, a key control module, an information display module, and a position detection module. The key control module includes a plurality of functional switches and functional keys. The signal control module has a plurality of key function execution commands respectively corresponding to the functional keys. The position detection module is configured for detecting a placement orientation of the portable electronic device. When the portable electronic device is rotated to change the placement orientation of the information display module, a screen orientation of an information display image provided by the information display module is changed following a change of the placement orientation of the information display module, and a corresponding relationship between the functional switch and the key function execution command is changed following the change of the placement orientation of the information display module.

The present invention includes an apparatus and method for detecting the location of one or more sources of one or more target molecule, the apparatus comprising: a molecule detector; and a processor connected to the molecule detector and to a global position system, wherein the processor calculates the presence of the one or more target molecules, runs a computer code that determines a dynamic reverse gas stack model for the one or more target molecules, and triangulates the possible position for a source or effluent of the one or more target molecules based on the dynamic reverse gas stack model. The determined reverse gas stack model may have a Gaussian dispersion over one or more sampled locations.

A method for pollutant sensor placement is described. Data about environmental characteristics across a geographic region is received from a plurality of environmental sensors. The geographic region includes one or more pollutant sources that emit a pollutant. The received data is transformed from one or more of the plurality of environmental sensors into common data having a common grid across the geographic region. The geographic region is divided into a plurality of sub-regions based on the common data. Locations within the geographic region are determined for placement of pollutant sensors based on estimated dispersion of the pollutant through the plurality of sub-regions.

A system for detecting an analyte gas in an environment includes a first gas sensor, a first contaminant sensor separate and spaced from the first gas sensor, and electronic circuitry in electrical connection with the first gas sensor to determine if the analyte gas is present based on a response of the first gas sensor. The electronic circuitry is further in electrical connection with the first contaminant sensor to measure a response of the first contaminant sensor over time. The measured response of the first contaminant sensor varies with an amount of one or more contaminants to which the system has been exposed in the environment over time.

In some embodiments, data from multiple vehicle-based natural gas leak detection survey runs are used by computer-implemented machine learning systems to generate a list of natural gas leaks ranked by hazard level. A risk model embodies training data having known hazard levels, and is used to classify newly-discovered leaks. Hazard levels may be expressed by continuous variables, and/or probabilities that a given leak fits within a predefined category of hazard (e.g. Grades 1-3). Each leak is represented by a cluster of leak indications (peaks) originating from a common leak sources. Hazard-predictive features may include maximum, minimum, mean, and/or median CH4/amplitude of aggregated leak indications; estimated leak flow rate, determined from an average of leak indications in a cluster; likelihood of leak being natural gas based on other indicator data (e.g. ethane concentration); probability the leak was detected on a given pass; and estimated distance to leak source.