Ethylene |
NO.172L |
| CH2¡§CH2 |  |
 |
Performance
| Measuring Range | 0.2 to 50 ppm | 50 to 100 ppm |
| Number of Pump Strokes | 4 | 2 |
| Correction Factor | 1 | 2 |
| Sampling Time | 2 minutes per pump stroke | |
| Detecting Limit | 0.05 ppm (n=4) | |
| Colour Change | Pale yellow → Blue | |
| Reaction Principle | CH2:CH2 + (NH4)2MoO4 + PbSO4O → Molybdenum blue | |
| Coefficient of Variation | 10% (for 0.2 to 10 ppm), 5% (for 10 to 50 ppm) | |
| 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 |
| Ammonia, Hydrogen cyanide | + | White | |
| Carbon monoxide, Hydrogen | + | Blue (whole layer) | |
| Hydrogen chloride | + | Pink | |
| Hydrogen sulphide | + | Black | |
| Butadiene | + | White | |
| Butane, Pentane | + | Blue (whole layer) | |
| Butylene, Propylene | 1/4 time | + | Blue |
| Calibration gas generation | High pressure gas cylinder method |
| TLV-TWA | TLV-STEL | Explosive range |
| 200ppm | - | 2.7 to 36% |
