Carbonyl sulphide |
NO.21LA |
| COS |  |
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Performance
| Measuring Range |
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| Number of Pump Strokes |
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| Correction Factor |
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| Sampling Time | 3 minutes per pump stroke | |||
| Detecting Limit | 0.8 ppm (n=2) | |||
| Colour Change | Bluish Purple → White | |||
| Reaction Principle | COS + I2O5 + H2SO4 → SO2 + CO2 SO2 + I2 + H2O → 2HI + H2SO4 |
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| Coefficient of Variation | 10% (for 5 to 20 ppm), 5% (for 20 to 50 ppm) | |||
| Shelf Life | 2 Years | |||
| 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 |
| Carbon monoxide | 500 ppm | + | Black |
| sulphur dioxide, Carbon disulphide | + | White | |
| Carbon dioxide | No | No | |
| Nitrogen dioxide | 2 ppm | + | Brown |
| Hydrogen sulphide | 1000 ppm | + | White |
| Propane, Butane | 10% | No | Black at the top of the discoloured area. |
| *In case the primary tube is totally discolours, analyzer tube will give white discolouration by hydrogen sulphide. |
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| Calibration gas generation | High pressure gas cylinder method |
| TLV-TWA | TLV-STEL | Explosive range |
| - | - | 12 to 19% |
