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

A method of synthesizing nitric oxide (NO) for a gas mixture, the method comprising the steps of:

• providing a flow of nitrous oxide (N2O) into a reaction chamber until the reaction chamber is purged of substantially all ambient air;
• exposing the flow of N2O to ultraviolet light in the reaction chamber provided by a light source;
• forming NO from the exposure of the flow of N2O to the ultraviolet light to create a N2O/NO source gas;
• collecting the N2O/NO source gas which exits the reaction chamber;
• and
• mixing the N2O/NO source gas with a flow of a diluent gas to form the gas mixture;
• wherein the gas mixture that results has a concentration of NO between approximately 1-270 ppbv, and a concentration of no more than 0.4% NO2.

A method of synthesizing nitric oxide (NO) mixed into a diluent gas to form a resultant gas, the method comprising:

• flowing nitrous oxide (N2O) into a reaction chamber, the reaction chamber substantially free of ambient air;
• exposing the N2O to ultraviolet light emitted from a light source at wavelengths shorter than 230 nm to form photolysis products, the N2O photolyzing to form the products NO and N2 or N2 and O2 at about a 3:2 ratio;
• flowing the photolysis products and unreacted N2O out of the reaction chamber;
• and
• mixing the photolysis products and unreacted N2O with a flow of the diluent gas to produce the resultant gas, the diluent gas scrubbed of NO before mixing;
• wherein the resultant gas has a concentration of NO>0 and ≤100 ppmv and a concentration of NO2≤0.4 ppmv;
• and
• wherein the concentration of NO in the resultant gas is controlled by varying at least one of the intensity of the light source, the flow of N2O and the flow of the diluent gas.

A method of synthesizing nitric oxide (NO) mixed into a diluent gas to form a resultant gas, the method comprising:

• flowing nitrous oxide (N2O) into a reaction chamber, the reaction chamber substantially free of ambient air;
• exposing the N2O to ultraviolet light emitted from a light source at wavelengths shorter than 230 nm to form photolysis products, the N2O photolyzing to form the products NO and N2 or N2 and O2 at about a 3:2 ratio, the reaction chamber sized so that absorption of the ultraviolet light is optically thick;
• flowing the photolysis products and unreacted N2O out of the reaction chamber;
• and
• mixing the photolysis products and unreacted N2O with a flow of the diluent gas to produce the resultant gas, the diluent gas scrubbed of NO before mixing;
• wherein the resultant gas has a concentration of NO>0 and ≤100 ppmv and a concentration of NO2≤0.4 ppmv;
• and
• wherein the concentration of NO in the resultant gas is controlled by varying at least one of the intensity of the light source, the flow of N2O and the flow of the diluent gas.