sulphur dioxide |
NO.5DH |
| SO2 |
 |
Performance
| Measuring Range | 10 to 600 ppm |
| Sampling Hours | 1 to 5 hours |
| Detecting Limit | 1 ppm (5 hours) |
| Colour Change | Bluish purple → White |
| Reaction Principle | SO2 + I2 +H2O → 2HI + H2SO4 |
| Coefficient of Variation | 10% (for 50 to 600 ppm¥hr) |
| Shelf Life | 3 Years |
| Corrections for temperature & humidity | Temperature correction is necessary |
| Store the tubes at cool and dark place. | |
Possible coexisting substances and their interferences (NOTE)
| Substance | Concentration | Interference | Change colour by itself to |
| Nitrogen dioxide |  |
No | |
| Hydrogen sulphide | + | White |
| Calibration gas generation | Permeation tube method |
| TLV-TWA | TLV-STEL | Explosive range |
| 2 ppm | 5 ppm | - |