Teledyne 6400EH - Sulfur Dioxide Analyzer - Manual (Page 32)

Optional Hardware/Software Model 6400EH
Teledyne Analytical Instruments 20
5.2 Internal Zero/Span Gas Generator (Option 51)
T he IZS valve option (OPT 51) is not available for the 6400EH.
5.3 Zero and Two Span Point Valve Option (OPT 52)
This option includes a special set of valves that allows two separate
SO
2
mixtures to enter the analyzer from two independent sources.
Typically these two gas mixtures will come from two, separate,
pressurized bottles of certified calibration gas: one mixed to produce a
SO
2
concentration equal to the expected span calibration value for the
application and the other mixed to produce a concentration at or near the
midpoint of the intended measurement range. Individual gas inlets,
labeled
HIGH SPAN
and
LOW SPAN
are provided at the back on the
analyzer.
The valves allow the user to switch between the two sources via
keys on the front panel or from a remote location by way of either the
analyzer’s digital control inputs or by sending commands over it’s serial
I/O port(s). The pneumatic diagram for instruments with the zero and
two span point valve option (OPT 52) is shown in Figure 5-2.
Note: The analyzer’s software only allows the SLOPE and
OFFSET
to be calculated when sample is being
routed through the HIGH SPAN inlet.
The LOW SPAN gas is for midpoint reference checks only.