Methyl Iodide |
NO.230 |
| CH3I |  |
 |
Performance
| Measuring Range | 0.5 to 1ppm | 1 to 20ppm | 20 to 46ppm | 46 to 108ppm |
| Number of Pump Strokes | 4 | 2 | 1 | 1/2 |
| Correction Factor | 0.5 | 1 | 2.3 | 5.4 |
| Sampling Time | 1.5 minutes per pump stroke | |||
| Detecting Limit | 0.2ppm (n=4) | |||
| Colour Change | White → Gray | |||
| Reaction Principle | CH3I + I2O5 + V2O5 + H2SO4 → I2 I2 + 3,3,5,5-Tetramethylbenzidine вк Reaction Products |
|||
| Coefficient of Variation | 5% (for 1 to 20ppm) | |||
| Shelf Life | 2 Year | |||
| Corrections for temperature & humidity | Temperature correction is necessary | |||
| Store the tubes in the refrigerator to keep at 10ºC (50ºF) or below. | ||||
Possible coexisting substances and their interferences (NOTE)
| Substance | Concentration | Interference | Change colour by itself to |
| Chlorine |  1/1 |
+ (Two layers) | Brown (turns pale blue after a few minutes) |
| Nitrogen dioxide | 1/1 |
 (Two layers) |
Pink |
| Methyl bromide |  30 ppm |
No | No |
| Dichloromethane | 50 ppm |
No | No |
| Carbon dioxide | 1% |
No | No |
| Calibration gas generation | Diffusion tube method |
| TLV-TWA | TLV-STEL | Explosive range |
| 2 ppm | - | - |
