Abstract: 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.

Abstract: 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 (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2) 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 Mm?1 or less for particulate matter, corresponding to ˜0.13 ?g/m3 or less for black carbon particulates.

Abstract: 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.

Abstract: The present invention provides a means of producing nitric oxide (NO) by photolysis of nitrous oxide (N2O) 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 NO2 gas 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.