Nitrogen oxides NO+NO2 NO.11S


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)

Color Change

White Pale green

Reaction Principle

Nitrogen oxides is oxidised by nitrogen dioxide,
then react with diphenylamine to produce
p-nitroso-diphenylamine which color is pale green.
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 color by itself

Hydrogen chloride

50 ppm

Faint demarcation

Produce Bluish purple
at 10 ppm

Ozone

80 ppm

Faint demarcation
2 layers

Pale brown

Sulfur dioxide,
Hydrogen sulfide

1/1

Plus error

No discoloration
Methanol

400 ppm

 Minus error No discoloration


Calibration gas generation NO2:Permeation tube method
NO:High pressure gas cylinder method


TLV-TWA TLV-STEL Explosive range
NO2:3ppm
NO:25ppm		 NO2:5ppm -


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