Application Range
Standard Measuring Range: 5 to 50 / 1 to 15 ppm
Number of Strokes n: 10 / 20
Time for Measurement: approx. 2 min / approx. 4 min
Standard : ± 10 to 15 %
Color Change: blue -> yellow
Ambient Operating Conditions
Temperature: 5 to 40 °C
Absolute Humidity: 3 to 15 mg H2O / L
Reaction Principle
HNO3 + bromophenol blue -> yellow reaction product
Cross Sensitivity
Hydrogen sulfide and nitrogen dioxide in the TLV range do not interfere, however, 50 ppm nitrogen dioxide gives an indication similar to 3 ppm nitric
acid. It is impossible to measure nitric acid in the presence of other mineral acids. Chlorine discolors the indication layer grey, and this makes it difficult
to evaluate the nitric acid indication. If chlorine is present in the TLV range, this leads to slightly higher nitric acid indications.