Nitrogen oxides

NO.11S
NO+NO2
Performance
Measuring Range
5 to 10 ppm 10 to 250 ppm 250 to 625 ppm
Number of Pump Strokes
2 1 1/2
Correction Factor
1/2 1 2.5
Sampling Time 1 minute per pump stroke
Detecting Limit 2 ppm (n=2)
Colour Change White → Pale green
Reaction Principle NO + Cr6+ + H2SO4 →NO2
NO2 + (C6H5)2NH Pale green product
Coefficient of Variation 10% (for 10 to 40 ppm), 5% (for 40 to 250 ppm)
Shelf Life 2 Years
Corrections for temperature & humidity Unnecessary
Store the tubes at cool and dark place.
Possible coexisting substances and their interferences (NOTE)
Substance Concentration Interference Change colour by itself to
Hydrogen chloride 50 ppm + Bluish purple (10 ppm)
Ozone 80 ppm two layers Pale brown
sulphur dioxide,
Hydrogen sulphide
1/1 + No
Methanol 400 ppm No
Calibration gas generation NO2:Permeation tube method
NO:High pressure gas cylinder method
TLV-TWA TLV-STEL Explosive range
NO2: 3 ppm
NO: 25 ppm
NO2: 5 ppm -


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