Author(s)

M. Doval, J. Barberá, E. González & F. J. Marzal

Abstract

The influence of sample pressure on chemiluminescence nitrogen oxides analyzers is studied in this paper. Although both of the employed analyzers comply with the requirements established in the standard EN 14211:2005 for this performance feature, it is advisable to make corrections to ensure a better quality of the data. The proposed procedure reduced to ± 1.5% the mistakes caused by the effect of sample pressure. Keywords: EN 14211:2005, nitrogen oxides, chemiluminiscence, pressure, correction procedure. 1 Introduction Networks measuring ambient air pollution within the Member States use, in general, analyzers certified by the Environmental Protection Agency of the United States as reference methods [2], although no European legislation in this matter obliges the analyzers to meet any special requirements, except as regards the analytical method employed. In order to improve emission quality data, the European Commission has elaborated the Proposal for a Directive on ambient air and cleaner air for Europe [3], which will replace the Framework Directive 96/62/EC [4] currently in force. The Proposal establishes new reference documents for the measurement of the gaseous pollutants regulated in this field. Nitrogen oxides (NO and NO2) receive special attention due to their effects on humans and the environment and for being tropospheric ozone precursors. The reference method for the measurement of these pollutants established in the

Keywords

EN 14211:2005, nitrogen oxides, chemiluminiscence, pressure, correction procedure.