Carbon monoxide |
NO.1La |
| CO |  |
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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 | 2 minutes per pump stroke | ||||
| Detecting Limit | 2 ppm (n=3) | ||||
| Colour Change | Yellow → Blackish brown | ||||
| Reaction Principle | CO + Na2Pd(SO3)2 → Pd + CO2 + SO2+Na2SO3 | ||||
| Coefficient of Variation | 10% (for 25 to 100 ppm), 5% (for 100 to 500 ppm) | ||||
| Shelf Life | 3 Years | ||||
| Corrections for temperature & humidity | Temperature 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 |
| Acetylene | 1/50 time | + | Dark brown |
| Ethylene | 2000 ppm | No | Brown (whole layer) |
| Hydrogen | 5000 ppm | + | Dark brown (whole layer)(1%) |
| sulphur dioxide | 1/10 time | + | Blackish brown |
| Nitrogen dioxide | 40 ppm | + | Red (60 ppm) |
| Carbon disulphide | 1/50 time | + | Dark brown |
| Halogens | 1/5 time | + | Dark brown |
| Mercaptans | 1/5 time | + | Dark brown |
| Hydrogen sulphide | 1/5 time | + | Dark brown |
| Calibration gas generation | High pressure gas cylinder method |
| TLV-TWA | TLV-STEL | Explosive range |
| 25 ppm | - | 12.5 to 74% |
