Application Range
Standard Measuring Range: 0.02 to 0.2 ppm
Discoloration compared to color comparison tube.
Number of Strokes n: 25
Time for Measurement: approx. 20 min
Standard Deviation: ± 30 %
Color Change: white -> orange
Ambient Operating Conditions
Temperature: 15 to 30 °C
Absolute Humidity: < 20 mg H2O / L
Reaction Principle
a) Pyridylpyridinium chloride + NaOH -> Glutaconaldehyde sodium oletate
b) 2,4-TDI (also for 2,6-TDI) + HCI -> Aromatic amine
c) Aromatic amine + glutaconaldehyde -> orange reaction product
Cross Sensitivity
Other isocyanates are not indicated.
No interference by:
5 ppm aniline
10 ppm benzylamine
5 ppm toluene
20 ppm benzene
Mercaptans also discolor the indicating layer.
Additional Information
Before carrying out the measurement the lower reagent ampoule must be broken and the liquid transferred to the indication layer, so that it changes
color to yellow. Next, the upper reagent ampoule must be broken and the liquid transferred to the indication layer, so that it returns to a white color.
After performing 25 pump strokes wait 15 minutes before evaluating the indication.