Abstract: A sampling system for capturing samples of trace elements in ambient air comprises a multi-port valve coupled to a plurality of sorbent tubes. Each tube is connected to the multi-port valve by means of pairs of the valve ports. The multi-port valve is constructed and operated in a predetermined sequence to create a flow path through the multi-port valve. The flow path directs an air sample to only one connected sorbent tube at a given time and for a given time interval.

Abstract: A gas detector having a sealed sensor assembly is only exposed to the ambient atmosphere when the detector is to be placed in the service. The detector is placed in the service by removing an elongated planar adhesive backed sealing member. The gas sensor also incorporates a replaceable biomemetic sensing material which is carried within a housing within the detector. The housing contains an internal region wherein the gas sensing material is located. The internal region is sealed where the housing is attached to a printed circuit board on one hand and by the removable sealing planar member on the other hand so as to protect the gas sensitive material from contamination or exposure to the atmosphere until the unit is placed into service.

Abstract: An ozone detector in the form of two basic embodiments which can measure ozone concentration in ambient air at 0.001-1 ppm. The first embodiment includes a stretched elastic material and a standard which can give ozone concentration in response to degree of microcracking or frosting of the elastic material. The second embodiment includes a chamber containing a long strip of elastic material, a component for stretching the material, a light source for generating a light and illuminating the film and a detector for detecting reflected, transmitted through or scattered light by the material.

Abstract: A gas concentration measuring apparatus is provided which measures the concentration of two kinds of gas components such as O2 and NOx contained in exhaust gasses of an internal combustion engine of automotive vehicles. The apparatus has a gas sensor which includes a first cell responsive to application of a voltage to discharge O2 in the exhaust gasses to the outside and produce an electric current as a function of concentration of the discharged O2 and a second cell responsive to application of a voltage to produce an electric current as a function of concentration of NOx in the exhaust gasses from which the O2 is discharged by the first cell. The apparatus offsets an error component of the electric current produced by the second cell which depends upon O2 contained in the exhaust gasses.

Abstract: A sensor and method for rapidly determining the absence of a vapor in a gas or fluid is described as well as a method for constructing the sensor. The sensor comprises a resistive element having first and second leads; an elastomeric material in thermal contact with and surrounding a portion of the resistive element; and a stratum of electrically conductive particles surrounding a portion of the elastomeric material and electrically coupled to the first lead and a third lead. The method for determining the absence of a vapor comprises linking the sensor to a control means for preventing excessive adsorption; exposing the sensor to an environment; and monitoring the sensor.

Abstract: An aerosol lab-on-a-chip (ALOC) integrates one or more of a variety of aerosol collection, classification, concentration (enrichment), and characterization processes onto a single substrate or layered stack of such substrates. By taking advantage of modern micro-machining capabilities, an entire suite of discrete laboratory aerosol handling and characterization techniques can be combined in a single portable device that can provide a wealth of data on the aerosol being sampled. The ALOC offers parallel characterization techniques and close proximity of the various characterization modules helps ensure that the same aerosol is available to all devices (dramatically reducing sampling and transport errors). Micro-machine fabrication of the ALOC significantly reduces unit costs relative to existing technology, and enables the fabrication of small, portable ALOC devices, as well as the potential for rugged design to allow operation in harsh environments.

Abstract: An analysis system and method for a cleanroom environment is disclosed wherein on-line testing of water-soluble contaminants is performed by condensing water vapor from an air sample taken from the clean room. The condenser is connected to a analyzing unit that is used to measure and analyze the water-soluble contaminants in the condensed water received from the condensing unit.

Abstract: A gas concentration measuring apparatus is provided which measures the concentration of two kinds of gas components such as O2 and NOx contained in exhaust gasses of an internal combustion engine of automotive vehicles. The apparatus has a gas sensor which includes a first cell responsive to application of a voltage to discharge O2 in the exhaust gasses to the outside and produce an electric current as a function of concentration of the discharged O2 and a second cell responsive to application of a voltage to produce an electric current as a function of concentration of NOx in the exhaust gasses from which the O2 is discharged by the first cell. The apparatus offsets an error component of the electric current produced by the second cell which depends upon O2 contained in the exhaust gasses, or which in related operations, depends upon any residual oxygen remaining in the second cell without being discharged by the first cell.

Abstract: A system for analyzing a content of at least one element of a contained atmosphere for soldering or tinning with a metal alloy, comprising: at least one sampling line for taking a gas sample from the contained atmosphere; at least one analyzer for analyzing the element; at least one coalescence filter located on the sampling line upstream of the analyzer; wherein the sampling line comprises a portion, located between the contained atmosphere and the coalescence filter, wherein the formation of cold spots which could cause precipitation of solid or pasty compounds in the line portion is prevented; a detector of a blockage in the sampling line between the enclosure and the analyzer.

Abstract: There are provided with a gas detecting sensor and a gas detecting device for controlling a ventilation system of a vehicle using the gas detecting sensor. The gas detecting sensor of the present invention includes two kinds of gas sensing layers separately formed and a heater assembly for heating the two sensing layers to different temperatures.

Abstract: The current invention discloses a wireless monitoring system. The system has one or more monitoring devices. Each device can transmit data to and receive messages from an output center or alarm system. The output center can also transmit and receive messages. Both the output center and each device preferably have a transceiver that enables both the transmission and receipt of messages. No remote terminal units or hardwiring is required for the system to function. The system is truly a wireless gas monitoring system. The system may use low earth orbit satellite technology, or licensed radio frequencies or any other means to wirelessly transmit and receive messages.

Abstract: An acoustic wave based-chemical sensor containing a crystal substrate and a coating of small particulate matter is disclosed. The small particulate matter can be graphite particles. Transducers are connected to the crystal substrate to generate an alternating potential across the crystal substrate, which in turn causes the crystal to resonate due to the converse piezoelectric effect. The coating absorbs the analyte, thus changing the mass of the sensor, and accordingly changing its resonant frequency. The transducers detect this change in resonant frequency to indicate that the analyte is present. The use of small particulate matter results in a coating having a large surface area which facilitates mass uptake of large amounts of VOCs, improved acoustic properties even with relatively thick coatings, and a high operational temperature range.

Abstract: An explosion-proof gas sensor (1) with a flashback barrier (2) permeable to the gas to be measured between the measuring space (4) and the environment in an otherwise gas-impermeable housing (3) is described. The sensor provides reduced response time and higher signal sensitivity for the gas to be measured. A flashback barrier (2) is provided including a plurality of flexurally rigid fabric layers made preferably of metal, which are permeable to the gas to be measured, with an overall thickness of one to ten mm, an overall porosity of at least twenty percent by volume relative to the volume of the flashback barrier (2), and with a maximum number of one percent of all pores with a pore size larger than 240 &mgr;m.