INTERCOMPARISON OF DIFFERENT AETHALOMETERS WITH AN ABSORPTION TECHNIQUE - LABORATORY CALIBRATIONS AND FIELD-MEASUREMENTS

The prototype of a new aethalometer was calibrated and tested in the laboratory by applying graphite, salt and iron oxide aerosol particles. It turned out that the response of the aethalometer was critical to the ratio of the mass of absorbing and non-absorbing materials. The aethalometer data from field measurements were compared with results gained by an optical absorption technique (Hanel's method). The correlations showed wide scattering, presumably due to different compositions of atmospheric particles. During field measurements the prototype was also compared with a commercial aethalometer of the "Hansen-type". The measured soot concentrations differed by about 50% on average. The results of the commercial aethalometer and the absorption technique agreed very well.