Ludlum Measurements, Inc.

2b Technologies, Inc.

Peter Christian Andersen

John William Birks

Craig Joseph Williford

Andrew Allen Turnipseed

Bova Xiong

Christopher M Ford

An enclosure or housing for an air monitoring instrument package for mounting on the roof or other surface on the outside of vehicles such as cars, trucks, buses, trams, trains and ships. By measuring air pollutants from moving vehicles, it is possible to explore the distribution of air pollutants throughout a city or rural area for the identification of sources of different pollutants, estimating human exposures to air pollutants, and mapping air pollutants with high resolution. The disclosed device provides continuous sampling of outside air while simultaneously protecting the delicate instruments from weather elements such as high wind, rain, snow, sleet and hail. The design also allows a nearly constant flow rate of sampled air independent of vehicle velocity. An optional impaction region further reduces transmission of mist and large particles to the chamber containing the measurement package.

Enclosure for mobile monitoring of the composition and properties of ambient air

The present invention makes use of a modular Folded Tubular Photometer to measure the concentrations of gas-phase species and/or particles, including especially air pollutants such as ozone (O), nitrogen dioxide (NO), sulfur dioxide (SO) and black carbon particulate matter, by means of absorbance of ultraviolet (UV), visible or infrared (IR) light. The optical bench makes use of modular components (tubes and mirror assemblies) that allow construction of path lengths of up to 2 meters or more while maintaining low detection cell volumes. The long path lengths, low cell volumes, and the innovation of pressure equalization during the absorbance measurements enable sensitive detection of ambient air pollutants down to low part-per-billion levels or less for gas species, and extinctions down to 1 Mmor less for particulate matter, corresponding to &#x2dc;0.13 &#x3bc;g/mor less for black carbon particulates.

Method for measuring air pollutants using a folded tubular photometer

The present invention provides a means of greatly reducing interferences from mercury vapor, UV-absorbing compounds and water vapor in the measurement of ozone by UV absorbance. A heated graphite scrubber destroys greater than 99% of ozone passing through it while reducing biases from typical atmospheric UV-absorbing interferents by large factors compared to conventional ozone scrubbers. Substitution of a heated graphite scrubber in place of traditional ozone scrubbers such as hopcalite, metal oxides and heated silver scrubbers, results in a more accurate measurement of ozone by reducing the responses to UV-absorbing interferences and water vapor. The heated graphite scrubber also may be used in combination with other ozone sensors, such as electrochemical and HMOS sensors, to provide a reference measurement with ozone selectively removed and thus greatly reduce contributions from interfering species in those measurement devices as well.

Heated graphite scrubber to reduce interferences in ozone monitors

The present invention provides a means of producing nitric oxide (NO) by photolysis of nitrous oxide (NO) at ultraviolet wavelengths. One application is the production of a known concentration of NO in a diluent gas for calibration of analytical instruments that measure nitric oxide in gases such as exhaled breath, ambient air and automobile exhaust. A potentially important medical application is the production of NO for inhalation therapy, an advantage being that very little toxic NOgas is produced. The method is useful for producing NO for industrial applications as well. Advantages of this method of NO production include the use of a single, inexpensive, readily available reagent gas of very low toxicity. Furthermore, the concentration of NO produced can be easily controlled by varying the ultraviolet (UV) lamp intensity and relative gas flow rates. The method may also be applied to the production of controlled concentrations of other gases as well such as CO and Fby using reagent gases other than NO.

Method to produce a calibration, reagent or therapeutic gas by exposing a precursor gas to ultraviolet light

The present invention provides a means of measuring the concentration of ozone dissolved in water or another solvent. Small, discrete samples are sparged with air or another unreactive gas for a short period of time to measure a profile of ozone vs time in the sparge gas. The total amount of ozone in the original sample is obtained by integrating under the ozone vs time profile. A correction may be made for ozone remaining in the sample after a finite sparge time by integrating under the profile tail using a decay constant obtained from the measured ozone vs time profile. The method differs from previous methods based on sparging of the sample in that a Henry's Law equilibrium or constant ratio of ozone present in the gas and liquid phases is not assumed and the flow rates of sample and sparge gas are not continuous.

Aqueous ozone monitor utilizing gas stripping

The present invention provides a means of greatly reducing or eliminating the interferences of UV-absorbing compounds, mercury, water vapor and particulates in the UV absorbance measurement of ozone by replacing the internal solid-phase ozone scrubber with a gas-phase scrubber. Reagent gases well suited as a gas-phase scrubber of ozone include nitric oxide and bromine atoms. Nitric oxide may be supplied by a gas cylinder or by photolysis of either NO or NO, both in the absence of oxygen. Bromine atoms are conveniently generated by photolysis of Brsupplied by a permeation tube. Bromine atoms have the advantage of having a faster reaction with ozone than NO and of being catalytic in their reaction. Nitric oxide has the advantage of being generally less reactive with other components of air.

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Superior, CO, United States of America

Peter Christian Andersen