Nitrogen oxides |
NO.11L |
| NO+NO2 |  |
 |
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 | 0.01 ppm (n=8) | ||||
| Colour Change | White → Yellowish orange | ||||
| Reaction Principle | NO + Cr6+ + H2SO4 →NO2 NO2 + o-Tolidine Yellowish orange product |
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| Coefficient of Variation | 10% (for 0.2 to 1 ppm), 5% (for 1 to 5 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 |
| Chlorine, Bromine, Chlorine dioxide |
+ | Yellowish orange | |
| sulphur dioxide | 25 ppm |  |
No |
| Hydrogen sulphide | 25 ppm | |
No |
| Calibration gas generation | NO2:Permeation tube method NO:High pressure gas cylinder method |
| TLV-TWA | TLV-STEL | Explosive range |
| NO2 : 3 ppm NO: 25 ppm |
NO2: 5 ppm | - |
