5Opsis AB. Quality assurance and quality control using Opsis analysers for air quality monitoring ( Version 1.4) [M]. Sweden:Opsis AB,2003:9-69.
6Thermo Electron Corporation. iPort instruction manual [ M ]. USA : Thermo Electron Corporation,2005 : 30-45.
7Stutz, Platt U. Numerical analysis and estimation of the statistical error of differential optical absorption spectroscopy measurements with least-squares methods [ J ]. Appl Optics, 1996,30:6041-6053.
8Platt U, Perner D. Simultaneous measurements of atmospheric CH2O,O3 and NO2 by differential optical absorption [ J ]. J Geophys Res, 1979,84 : 6329-6335.
9Platt U,Perner D. Detection of NO3 in the polluted troposphere by differential optical absorption [ J ]. Geophys Res Lett, 1980,7:89-92.
10Alvinc R. Methods of multivariate analysis[ M ].2nd ed. Canada : John Wiley&Sons, Inc, 2002.