The harmonisation of EC air quality directives : The control of the sampling lines in the air quality networks
A presentation of the existing norms for sampling lines is made, stressing the need for a better normalisation and showing the disparity of the sampling manifolds in the European networks. The importance of the sampling lines on the measurement quality is illustrated by the results of the quality assurance programme realised by the CLAP in 1987/88 in the EC air quality networks. For SO(2) measurement, when the absorption effect by the sampling manifold amounted to an average of 10% for all the measuring stations visited, far larger values were observed for individual stations. In order to evaluate the efficiency of the sampling lines, a test atmosphere generator has been designed and constructed, allowing for the introduction of a control gas mixture at the level of the sampling head of the stations. The first tests using this instrument in field conditions, conducted on two measuring stations in Northern Italy, have shown absorption effects to be 5% for nitrogen oxides and up to 40% for SO(2) measurements. This test atmosphere generator will be implemented by the CLAP in the new quality assurance programme to be organised in 1993.
Bibliographic Reference: Paper presented: Les Journées de la Qualité de la Mesure, Le Havre (FR), Oct. 2-4, 1991
Availability: Available from (1) as Paper FR 36541 ORA
Record Number: 199210058 / Last updated on: 1994-12-02
Original language: fr
Available languages: fr