Name of Gas |
SO2 tube |
H2S tube |
SO2 tube |
H2S tube |
SO2 tube |
H2S tube |
|
Measuring Range |
0.25 to
0.5 |
1.25 to
2.5 |
0.5 to 10 |
2.5 to
60 |
10 to 20 |
60 to 120 |
|
Number of Pump Strokes |
|
Correction Factor |
|
Sampling Time |
1.5 minute per pump stroke |
Detecting Limit |
0.05 ppm (n=2) |
Colour Change |
SO2tube : Yellowish green → Yellow
H2S tube : White → Brown |
Reaction Principle |
SO2tube:
SO2 + BaCl2+ H2O → BaSO3 + 2HCl
HCl + Base → Chloride
H2S tube:
H2S + Pb(CH3COO)2 → PbS + 2CH3COOH |
Coefficient of Variation |
SO2 tube: 10% (for 0.5 to 2 ppm), 5% (for 2 to 10 ppm)
H2S tube:10% (for 2.5 to 10 ppm), 5% (for 10 to 60 ppm) |
Shelf Life |
3 Years |
Corrections for temperature & humidity |
Unnecessary |
Store the tubes at cool and dark place. |