Measuring Range 5 to 10 ppm 10 to 250 ppm 250 to 625 ppm Number of PumpStrokes 2 1 1/2 CorrectionFactor 1/2 1 2.5 Sampling Time 1 minute per pumpstroke Detecting Limit 2 ppm (n=2) Color Change White → Palegreen Reaction Principle NO + Cr6++ H2SO4→NO2 NO2 + (C6H5)2NH 仺 Pale green product Coefficient ofVariation 10% (for 10 to 40ppm), 5% (for 40 to 250 ppm) ShelfLife 2Years Correctionsfor temperature & humidity Unnecessary Store the tubes at cool and darkplace.