Hydrogen cyanide |
NO.12LL |
| HCN |  |
 |
Performance
| Measuring Range | 0.2 to 7 ppm |
| Number of Pump Strokes | 2 |
| Correction Factor | 1 |
| Sampling Time | 2 minutes per pump stroke |
| Detecting Limit | 0.05 ppm (n=2) |
| Colour Change | Yellow → Pink |
| Reaction Principle | 2HCN + HgCl2 → Hg(CN)2 + 2HCl HCl + Base → Chloride product |
| Coefficient of Variation | 10% (for 0.2 to 2 ppm), 5% (for 2 to 7 ppm) |
| Shelf Life | 2 Years |
| Corrections for temperature & humidity | Humidity 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 |
| Hydrogen sulphide | 1 ppm | + | Red |
| sulphur dioxide | 1 ppm | + | Red |
| Calibration gas generation | Permeation tube method |
| TLV-TWA | TLV-STEL | Explosive range |
| - | C 4.7 ppm | 5.6 to 40% |
