Breath sensor apparatus and methods of use are described herein where a flow control apparatus may generally comprise a sampling chamber defining a volume and one or more openings into the sampling chamber, at least one sensor in fluid communication with the sampling chamber, wherein the at least one sensor is configured to detect the analyte. The sampling chamber may also be configured to receive the breath sample into the sampling chamber and into contact with the at least one sensor via diffusion into the sampling chamber.

Embodiments of the present specification provide methods and systems for maintaining accuracy and precision of calibration for a detector. The methods and systems include reducing the humidity of an internal calibration assembly by directing flow path of dry air periodically through the internal calibration assembly.

Provided is a system for detection and discrimination of gases, such as volatile organic compounds (VOCs), in a sample comprising two chambers, a first chamber equipped with a crystalline microporous material (CMM) and a second chamber equipped with a gas detector. A gas sample is introduced first into the second chamber for detection by the gas detector and is then re-routed to the first chamber for adsorption/desorption on the CMM. The gas detector in the second chamber produces electronic signals that correspond to the adsorption/desorption profile for the gas, which allows for discrimination of the gas in the sample from other possible gas samples.

A humidity reduction apparatus and a method for reducing the humidity of a volume of gas. The humidity reduction apparatus comprises a gas delivery conduit, at least one heat-conductive media positioned in-line within at least a portion of the gas delivery conduit, and a cooler in contact with at least a portion of the gas delivery conduit to cool the gas delivery conduit and the at least one heat-conductive media. The gas delivery conduit comprises at least one conducting portion. The first side of the cooler is configured to cool the at least one conducting portion of the gas delivery conduit and the at least one heat-conductive media. The voltage applied across the cooler is selectably reversed such that the first side heats the at least one conducting portion of the gas delivery conduit and the at least one heat-conductive media.

The invention relates to a device having an opening defining a fluid connection between a fluid channel in the device and ambient air, a sensor coupled to the fluid channel, configured to sense at least one component of the ambient air, and a micro fluid actuator connected downstream of the sensor, configured, in the suction stroke, to suck in fluid through the fluid channel and to transport the same towards the sensor, and, in the pressure stroke, to transport the sucked-in fluid through said fluid channel back towards the opening. According to the invention, the sensor is arranged spaced apart from the opening, and the volume of the fluid channel between the sensor and the opening is equal to or smaller than the stroke volume which the micro fluid actuator may convey with a single suction stroke.

A particle detecting module includes a main body, a particle monitoring base, an actuator, a heater and a sensor. The main body has a first and a second compartment. The main body has an inlet, a hot gas exhausting opening and an outlet. The inlet and the hot gas exhausting opening are in fluid communication with the first compartment. The outlet is in fluid communication with the second compartment. A communicating opening is communicated with the first and the second compartment. The particle monitoring base is disposed between the first compartment and the supporting partition plate. The first compartment is heated to maintain a monitor standard level of humidity in the first compartment. The sensor is disposed adjacent to the supporting partition plate and located in a monitoring channel of the particle monitoring base, thereby monitoring the gas. The particle detecting module can be applied to a slim portable device.

A filter that is used in conjunction with a non-specific gas sensor for PAA, which allows specific detection of PAA vapor in the presence of hydrogen peroxide vapor through the removal of the hydrogen peroxide vapor. The filter contains a filter catalyst that will catalyze the disproportionation of hydrogen peroxide but not react with PAA vapor, thus removing the hydrogen peroxide vapor and allowing the peracetic vapor to pass through the filter to the sensor.

A test device for testing of an oxygen sensor uses a compressor to draw air from an external environment and deliver compressed air into a gas separation unit. A gas separation membrane is located in a passage of the gas separation unit such that compressed air from the compressor travels through the passage and passes through the gas separation membrane. The gas separation membrane separates at least one of nitrogen and oxygen from the compressed air to produce a calibration gas having a calibrated amount of oxygen that is different from an amount of oxygen in the air. The calibration gas coupling is configured to be fluidly connected to the oxygen sensor such that the calibration gas is deliverable from the calibration gas coupling to the oxygen sensor.

The invention relates to an electrochemical gas sensing apparatus for sensing one or more analytes, such as NO.sub.2 and/or O.sub.3, in a sample gas and a method of using same. The apparatus uses Mn.sub.2O.sub.3 as a filter for ozone. The Mn.sub.2O.sub.3 may take the form of a powder which may be unmixed, mixed with various PTFE particles sizes, formed into a solid layer deposited onto a membrane and/or pretreated with NO.sub.2.

A particle collecting apparatus includes a cylindrical housing, a gap forming unit, a supply port and an intake port. The cylindrical housing has a closed top and an open bottom facing a target object. The gap forming unit is configured to form a gap having a predetermined distance between the bottom and the target object. The supply port is formed at the opening of the bottom in an annular shape along an inner wall of the housing and configured to supply a gas to the target object. The intake port is provided closer to a central axis of the supply port than the supply port and configured to suck particles on the target object.