Hello
I would like to seek some guidance on how to Calculate NOx(NO2 basis) in mg/m3:
I would like to calculate from known value of NO in mg/ m 3 to NO2 in mg/m3 at reference O2. I don't have ppm values.
NO basis:
NOx(NO ) in mg/m3 = lets assume 800mg/m3 at 7%O2
I would like to request an answer for NOx(NO2) in mg/m3 at 6% reference O2
I don't know NO,NO2 values in ppm. IF we convert NO to NO2 is that going to be accurate?
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Please check my methodology as shown below. I use the below method to calculate NOx(NO2 basis) emissions.
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My normal calculation method:
I believe below method is more accurate than the above method of conversion because we measure NO and NO2 in ppm and then converting to mg/m3.
I measure NOx from portable gas analyser where I can measure NO in ppm and NO2 in ppm and the device can calculate that as NOx in mg/m3 . This device uses NO2 basis (NO2 molecular weight is used) for final conversion
NOx ppm = NO ppm + NO2 ppm(both measured)
NOx mg/m 3 = NOx in ppm X mol.wt of NO2/22.4(molar volume)
Then I convert to reference O2
Lets assume measured O2 is 7% for NOx and reference O2 is 6%.
O2 correction = (20.95-Ref O2)/(20.95-Measured O2)
O2 correction = 1.0716
Final equation NOx(NO2) mg/m 3 = NOx(NO2) mg/m3 * (O2 correction factor 1.0716)
Please let me know your opinion.
Thanks