Hydrogen cyanide |
NO.12D |
| HCN |
 |
Performance
| Measuring Range | 1 to 200 ppm |
| Sampling Hours | 1 to 10 hours |
| Detecting Limit | 0.3 ppm (10 hours) |
| Colour Change | Yellow →@Pink |
| Reaction Principle | Hydrogen Cyanide reacts with the reagent to form intermediate material which stains indicator pink . |
| Coefficient of Variation | 10% (for 10 to 200 ppm-hr) |
| Shelf Life | 2 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 |
| Basic gases |  |
No discolouration | |
| Acid gases | + | Pink | |
| Nitrogen Dioxide |  0.5ppm |
+ | Pink |
| Hydrogen Sulphide | + | Pink |
| Calibration gas generation | Permeation tube method |
| TLV-TWA | TLV-STEL | Explosive range |
| - | C 4.7 ppm | 5.6 to 40% |