2
Portable Analyzer Testing Programs
Ø1996 GRI tested 6 models of compliance level “Emission Analyzer”.  Results of testing showed consistent laboratory performance, typically within 1%. 
Ø2000 EPA ETV tested seven multi-gas models
Ø 6 within about 1% 
Ø 1 within about 5%. 
ØEuropean TUV – Approval for official NOx testing since early 1990s (on-going approval process)