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.

Abstract: 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.

Abstract: A system for the indirect detection of agglutination in an agglutination assay using optical density measurement and a reaction vessel. Light emitted by light source is transmitted through reaction vessel containing components of an agglutination reaction that is detected by light detector. As particles in the reaction vessel settle in the absence of agglutination they are concentrated in a reaction vessel lower volume and increase the optical density of the light path through the reaction vessel. Light detector generates an output signal related to said optical density. Said output signal is read and interpreted by an instrument to detect a presence or absence of agglutination. Other embodiments are described and shown.

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 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. Instead, discrete samples are analyzed by nearly complete sparging.

Abstract: 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 N2O or NO2, both in the absence of oxygen. Bromine atoms are conveniently generated by photolysis of Br2 supplied 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.

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.

Abstract: 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 N2O or NO2, both in the absence of oxygen. Bromine atoms are conveniently generated by photolysis of Br2 supplied 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.

Abstract: The present disclosure provides a means of greatly reducing the interference of mercury vapor in the UV absorbance measurement of ozone. Currently, commercial ozone monitors make use of a low pressure Hg lamp as the radiation source. Because the lamp spectral lines are extremely narrow and resonant with the Hg vapor absorption spectrum, ozone monitors typically detect Hg with approximately three orders of magnitude greater sensitivity than ozone itself. The replacement of the low pressure mercury lamp with a broad band UV source centered near 254 nm greatly reduces the Hg interference. The optimal band width (FWHM) for the radiation source is approximately 1-10 nm. For band widths in this range, the Hg interference is reduced by a factor of 140 (for 1 nm) to 1,400 (for 10 nm) with minimal effect on the sensitivity toward ozone and linear dynamic range.