Detection of sulphur dioxide and nitrogen oxides by means of the ionization method: Comparison with the UV‐fluorescence method and the chemiluminescence method

摘要

AbstractComparison measurements between the ionization gas analytical system (AIG‐2) for detecting sulphur dioxide from ambient air and a monitor based on the UV‐fluorescence method were performed. The experiments included both laboratory tests at two laboratories with different calibration devices, and field periods in two different cities. According to the laboratory tests the reproducibility of the AIG‐2 was within 7.5 per cent over two years. During the first measurements the response ratio of the monitors was 1.5 on average for both laboratory and field measurements. After maintenance the response ratio was nearly 1.0 in the laboratory measurements and 0.9 in the field measurements. The drift of the AIG‐2 was 0.89 per cent per month. In addition to the comparison of monitors, the stability of the AIG‐2 also facilitates the comparison of different calibration methods between two laboratories. A maximum difference of 15 per cent and a minimum difference of 2 per cent between the output of the calibration devices of the two laboratories was found. We also discovered that the sample matrices of different calibration devices are different (e.g. moisture, inhomogeneities, particles), which can cause problems even when the calibration concentration is the same. As an example of the ve