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OFR185-iN2O, OFR254-iO3-iN2O
|
OH
|
O3 + H2O + N2O
|
185, 254
|
- Recommended method for low-NOx or variable-NOx OH generation over equivalent photochemical aging timescales of 1 - 10 days.
- Use OFR185 or OFR254 + ozone chamber with sufficient H2O to facilitate O(1D) + H2O --> 2OH.
- Use N2O to facilitate NOx production via N2O + O(1D) --> 2NO, NO + O3 --> NO2 + O2 ; "OFR185"
will produce additional O(1D) (and consequently, NOx), from N2O photolysis at 185 nm. Some NO3 radical is produced as byproduct of
NO2 + O3 reactions.
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OFR254-iPrONO,
OFR350-iPrONO,
OFR369-iPrONO
|
OH
|
iPrONO (isopropyl nitrite); testing of additional alkyl nitrites ongoing
|
254, 350, 369
|
- Recommended method for high-NOx OH generation over equivalent photochemical aging timescales less than 1 day, or if O3 or NO3 obtained
using OFR185-iN2O or OFR254-iO3-iN2O is problematic, or if 254 nm photolysis is problematic.
- Recommended photolysis wavelength = 369 nm if using isopropyl nitrite, or 350 nm if using methyl nitrite. At this time do not recommend 254 nm photolysis unless other
wavelengths are not available. Aerodyne will update recommendations pending further testing and evaluation.
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