MeasuringRange 0.04 to 0.08ppm 0.08 to 0.2ppm 0.2 to 5.0 ppm 5.0 to 16.5ppm Number of Pump Strokes 8 4 2 1 CorrectionFactor 0.2 0.4 1 3.3 SamplingTime 2 minutes per pumpstroke DetectingLimit 0.01ppm(n=8) ColorChange White → Yellowishorange ReactionPrinciple NO + Cr6++ H2SO4→NO2 NO2 + o-Tolidine 仺 Yellowish orangeproduct Coefficient ofVariation 10% (for0.2 to 1 ppm), 5% (for 1 to 5 ppm) ShelfLife 3Years Correctionsfor temperature & humidity Unnecessary Store the tubes at cool and darkplace.
Possible coexisting substances and theirinterferences (NOTE)
Substance Concentration Interference Change color by itself Chlorine,Bromine, Chlorine dioxide - Plus error Produce similarstain Sulfurdioxide 25 ppm Minus error Nodiscoloration Hydrogensulfide 25 ppm Minus error Nodiscoloration