RAF Ozone Photometer

• The HIAPER GV dual-beam, ultraviolet absorption ozone photometer is designed to measure atmospheric ozone mixing ratios in flight by ultraviolet absorption of a flowing air sample in a dual-beam, temperature-controlled sample cell. It is configured for either autonomous or interactive operation within the cabin of the HIAPER GV aircraft. Graphical user interface software provides real-time and post-flight data processing and analysis capabilities for rapid data evaluation and archival. The instrument has been fully inte grated on the GV aircraft.  The accuracy of its ozone measurements has been extensively characterized and validated through laboratory intercomparisons with an earlier-generation, previously validated flight instrument.
  
   
• Absorption is measured as the difference in light intensity between the cell filled with ozone laden air (ambient) vs. ozone-free air (scrubbed). Light intensity is converted to voltage and then to frequency; frequency ratio is the measure of ozone number density. Measurement of pressure and temperature in the instrument is then used to convert number density to mixing ratio in ppbv.
  
  
  
  Note: OP-1 is a HAIS-acquired instrument. OP-2 is a separate acquisition and is thus not a HAIS instrument.

Alternate name: Autonomous Airborne Ozone Photometer