Hydrogen cyanide |
NO.12D |
| HCN |  |
 |
Performance
| Measuring Range | 1 to 200 ppm |
| Sampling Hours | 1 to 10 hours |
| Detecting Limit | 0.4 ppm (10 hours) |
| Colour Change | Yellow → Red |
| Reaction Principle | 2HCN + HgCl2 → Hg(CN)2 + 2HCl HCl + Base → Chloride |
| Coefficient of Variation | 10% (for 10 to 200 ppm-hr) |
| Shelf Life | 3 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 |
| Ammonia |  |
No | |
| Nitrogen dioxide | + | Red | |
| Hydrogen sulphide | + | Red | |
| Amines | |
No |
| Calibration gas generation | Permeation tube method |
| TLV-TWA | TLV-STEL | Explosive range |
| - | C 4.7 ppm | 5.6 to 40% |
