Application Range
Standard Measuring Range: 1 to 10 ppm / 4 to 40 mg/m3
Number of Strokes n: 30
Time for Measurement: in air: approx. 15 min
in natural gas: approx. 10 min
Standard Deviation: ± 15 to 20 %
Color Change: violet -> yellow brown
Ambient Operating Conditions
Temperature: 0 to 35 °C
Absolute Humidity: < 30 mg H2O / L
Reaction Principle
THT + KMnO4 -> yellow brown reaction product
Cross Sensitivity
Up to 10 ppm hydrogen sulfide is adsorbed in the pretube, causing a brown discoloration. It is impossible to measure tetrahydrothiophene in the
presence of mercaptans. Up to 100 ppm of olefines (e. g. ethene, propene) will cause the color of the indicating layer to become lighter, at higher concentrations the olefins are also indicated. Up to 200 ppm methanol does not interfere.
Extension of Measuring Range
1.6 to 16 ppm / 6.4 to 64 mg/m3
n = 20 multiply the reading by 1.6