COMPARISON OF PASSIVE OZONE MONITORING ME THODS AT MONITORING SITES IN THE ALPINE AREA

In a joint European project under the leadership of the Research Centr e for Environment and Human Health, Neuherberg, in 1992 comparison of different passive ozone monitoring methods was carried out at 6 monito ring sites, representing high mountain areas, alpine mountain valleys, rural sites in lowland and highly polluted urban sites. A thorough ca libration program for the continuous UV ozone monitors was performed, so that the accuracy of the monitors could be to lie within +/- 5%. Fo r the passive samplers, the following principles were applied : tube t ype samplers with chemisorption of ozone by di(pyridyl)ethylene, batch type with the same absorption principle, indigo color change of Indig o on impregnated filters, tube type sampler equipped with indigo, surf ace active monitoring with potassium iodide on a glass fiber filter. T he correlation coefficients between passive devices and continuous ozo ne monitors varied from 0.91 to 0.33 for weekly, and from 0.84 to 0.62 for fortnight exposures and most devices followed the concentration t rends well over the 22 week observation period.