A method for determining a false negative rate of mobile monitoring and requisite number of mobile monitoring vehicles. The method focuses on road network of an urban area, by installing air pollution detection equipment on the mobile monitoring vehicles, to monitor air quality of the urban area. The method includes establishing a curve model of monitoring times for the mobile monitoring vehicles, determining two parameters of expected indicator: covered range, number of scheduled detections; and finding out a requisite number (C.sub.0) of the mobile monitoring vehicles, corresponding to a curve model which meets the two parameters of expected indicator.

An apparatus, method and sensor for measuring gas concentration. The apparatus includes a sensing unit and a processing unit. The sensing unit includes a first selective water vapour-permeable membrane, a first working electrode and a second working electrode. The first selective water vapour-permeable membrane allows the first working electrode to be in contact with water molecules while to prevent this first working electrode from being in contact with the gas molecules to be measured. The first working electrode generates an electrical signal caused by change in relative humidity, the second working electrode generates a superimposed electrical signal caused by the change in relative humidity and the gas molecules to be measured, and the processing unit acquires concentration of the gas based on the electrical signal and the superimposed electrical signal.

An air quality notification device is disclosed. The air quality notification device includes an actuating and sensing module, a microprocessor, a first communication module and a power source. The actuating and sensing module includes a sensor and an actuating device. The actuating device is disposed near the sensor. The sensor senses air transmitted by the actuating device to generate air quality information. The microprocessor is electrically connected to the actuating and sensing module. The first communication module is electrically connected to the actuating and sensing module to receive and transmit the air quality information. The power source is electrically connected to the microprocessor.

A method of measuring a gas concentration is described. The method comprises illuminating, with a light source, a volume of space that includes a gas and measuring, with a detector, a first illumination level of the volume of space. The method further comprises determining, via a processor, a gas concentration in the volume of space based on the measured first illumination level, where the volume of space is configured to be in fluid communication with a gas recirculation flow path including a catalyst, the catalyst configured to substantially remove the gas from the volume of space.

Highly accurate oxygen sensors made of graphene and titanium dioxide hybrid material are provided. With UV illumination, the disclosed sensors are capable of detecting O.sub.2 gas at room temperature and ambient pressure. The sensors are able to detect oxygen at concentrations ranging from about 0.2% to about 10% by volume under 365 nm UV light, and at concentrations ranging from 0.4% to 20% by volume under short wave UV light. The disclosed sensors have fast response and recovery times and can also be used to detect ozone.

A system and method for monitoring air quality is disclosed. A housing for an electronic display has a first pathway which extends between an ingestion area and an exhaustion area. An air quality monitoring device is located along said pathway and has one or more sensors that measure the concentration of various gases. The air quality monitoring device has a housing with a second pathway which connects an entrance aperture to exit aperture. The entrance aperture being configured to permit a portion of the ambient air in the first pathway to enter the second pathway.

A device includes a main body and at least one actuating and sensing module. A length of the main body is 5˜40 mm. A width of the main body is 5˜27 mm. A height of the main body is 2˜10 mm. The actuating and sensing module is disposed in the main body. The actuating and sensing module includes a carrier, at least one sensor, at least one actuating device, a driving and transmitting controller and a battery. The sensor, the actuating device, the driving and transmitting controller and the battery are disposed on the carrier. The actuating device is disposed on one side of the sensor. The actuating device includes at least one guiding channel. The actuating device is enabled to transport fluid to flow toward the sensor through the guiding channel so as to make the fluid measured by the sensor.

An electric meter includes a meter shell configured to be within an outer utility box. A meter socket and blades are for coupling to openings of the socket. The openings include utility-side and premises-side openings for the blades to extend into. A meter processor is coupled to measurement circuitry, and to a communications unit including a transceiver. A gas sensor is positioned proximate to the blades for sensing ≥1 gaseous compound product resulting from an arc discharge across air involving the blades. During operation of the electric meter, responsive sensing a presence of the gaseous compound product, the gas sensor generates an output signal. Responsive to the output signal being above a predetermined threshold level, the electric meter triggers an alert signal that is transmitted to an advanced metering infrastructure (AMI) which indicates an identity of the electric meter and that the electric meter had experienced the arc discharge.

A micro-colorimetric sensor for sensing target chemicals using edge tracking includes a substrate. A plurality of parallel linear channels of porous media is entrenched into the substrate and each linear channel includes a sensing material adapted to sense one of several specific target chemicals in air. The plurality of parallel linear channels is separated by barrier material from the adjacent parallel linear channel where the barrier material blocks diffusion of chemicals from one linear channel to another. A plate is affixed over the substrate top to cover the plurality of parallel linear channels. An air sample is diffused along the micro-colorimetric sensor and color images are captured. An intensity profile is derived from the plurality of color images to determine a maximum and a minimum intensity value along the sensor. A plurality of positions along the sensor is tracked to determine an edge position.

A micro-colorimetric sensor for sensing target chemicals that converts time sequence information into a spatial distribution of color. By tracking the spatial color distribution, chemical exposure over time is thus detected, which overcomes the limitation of traditional colorimetric sensors. A porous media is coated on a top surface of the substrate. Multiple sensing chemicals are fused in parallel linear channels into the porous media coating. A plate is affixed over the substrate top surface to cover the plurality of parallel linear channels. An air sample is diffused along the porous media to get a clear pattern of spatial color distribution and color images are captured. Optical parameters like gradient of spatial color distribution, intensity, and absorbance, etc., can be tracked to calculate analytes concentrations.