Hydrogen sulphide |
NO.4D |
| H2S |
 |
Performance
| Measuring Range | 0.2 to 200 ppm |
| Sampling Hours | 1 to 48 hours |
| Detecting Limit | 0.2 ppm (10 hours) |
| Colour Change | White → Brown |
| Reaction Principle | H2S + Pb(CH3COO)2 → PbS + 2CH3COOH |
| Coefficient of Variation | 10% (for 10 to 200 ppm-hr) |
| Shelf Life | 3 Years |
| Corrections for temperature & humidity | Unnecessary |
| 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 | ¡æ 5 ppm |  |
No |
| Ammonia | ¡å 25 ppm | No | No |
| Chlorine | ¡å 1 ppm | No | No |
| sulphur dioxide | ¡å 5 ppm | No | No |
| Calibration gas generation | Permeation tube method |
| TLV-TWA | TLV-STEL | Explosive range |
| 1 ppm | 5 ppm | 4.0 to 44% |