Instruction manual

120-00004 REV A 10/6/2011 4000 DIGITAL MANUAL PAGE 9
2.1 Zeroing the Analyzer
The Analyzer must always be zeroed, prior to use.
Zero adjustments must be made in the SAMPLE mode, i.e. with
the pump on, in air free of interfering gases. If necessary, use zero
air or a C-12 filter (provided) to zero in the sampling area. When
using C-12 zero filter, connect externally to gas inlet. Allow reading
to stabilize, before making final zero adjustment, (stabilization can
take approximately 20 minutes). The C-12 filter must be removed
after zeroing the analyzer.