he Model 714 NO2/NO/O3 Calibration Source combines our Model 408 Nitric Oxide Calibration Source™ with our Model 306 Ozone Calibration Source™ to provide a highly portable transfer standard for three pollutant gases without the need for a compressed cylinder of nitric oxide.
Calibrated concentrations of O3 are produced by photolysis of oxygen in scrubbed ambient air, and calibrated concentrations of NO are produced by photolysis of nitrous oxide, N2O, via a patented process,
N2O + light –> N2 + O*
O* + N2O –> 2 NO
where O* is electronically excited oxygen atoms (U.S. Patent No. 10,207,927). In addition, calibrated concentrations of NO2 are produced by gas phase titration (GPT) of NO with O3 using the same method as conventional GPT NO/NO2 calibrators. The concentrations of all three pollutant gases are directly traceable to the NIST photometric standard for ozone – eliminating uncertainties associated with the stability of nitric oxide standards.
Nitrous oxide is provided by disposable 8 or 16 oz cartridges typically used for making whipped cream, eliminating the requirement for a compressed gas cylinder and thereby enhancing safety and portability. The Model 714 is designed to accompany sales of our new FEM Model 405 nm NO2/NO/NOx Monitor and replace current calibration systems for all ozone, NO and NO2 monitors. The Model 714, which has an intuitive touch screen user interface, is provided in a rack mount-sized instrument case matching that of the Model 405 nm.
We recently published a journal article describing the Model 714 NO2/NO/O3 Calibration Source:
Portable calibrator for NO based on the photolysis of N2O and a combined NO2/NO/O3 source for field calibrations of air pollution monitors, Atmospheric Measurement Techniques (2020), 13, 1001-1018.