Teledyne 9110EH - Nitrogen Oxides Analyzer - Manual (Page 167)

Model 9110EH Instruction Manual Instrument Maintenance
• Unscrew the black aluminum cover of the IZS oven (3 screws) using a medium
Phillips-head screw driver. Leave the fittings and tubing connected to the cover.
• Remove the old permeation tube if necessary and replace it with the new tube. Make
sure that the tube is placed into the larger of two holes and that the open
permeation end of the tube (plastic) is facing up.
• Re-attach the cover with three screws and make sure that the sealing O-ring is
properly in place and that the three screws are tightened evenly.
• Replace the analyzer cover, plug the power cord back in and turn on the analyzer.
• Carry out an IZS span check to see if the new permeation device works properly.
The permeation rate may need several days to stabilize.
WARNING
Do not leave instrument turned off for more than 8 hours without removing the
permeation tube. Do not ship the instrument without removing the permeation
tube. The tube continues to emit NO
2
, even at room temperature and will
contaminate the entire instrument.
9.3.7. Changing the External Zero Air Scrubber
The external zero air scrubber contains two chemicals, pink Purafil © and
black, charcoal. The Purafil © converts NO in the ambient air to NO
2
and the
following charcoal absorbs any NO
2
. The chemicals need to be replaced periodically
according to Table 9-1 or as needed. This procedure can be carried out while the instrument
is running. Make sure that the analyzer is not in ZERO calibration mode.
• Locate the scrubber on the outside rear panel. Figure 3-7 shows the location,
Figure 9-4 the exploded assembly.
• Remove the old scrubber by disconnecting the 1/4” plastic tubing from the particle
filter using 9/16” and 1/2" wrenches.
• Remove the particle filter from the cartridge using 9/16” wrenches.
• Unscrew the top of the scrubber canister and discard the Purafil
© and charcoal
contents. Make sure to abide to local laws about discarding these chemicals. The
rebuild kit (listed in Appendix B) comes with a Material and Safety Data Sheet, which
contains more information on these chemicals.
• Refill the scrubber with charcoal at the bottom and the Purafil © chemical at the top
and use three, white retainer pads to separate the chemicals as shown in Figure 9-4.
• Replace the screw-top cap and tighten the cap - hand-tight only.
• If necessary, replace the DFU filter with a new unit and discard the old. The bottom
retainer pad should catch most of the dust, the filter should not be visibly dirty (on
the inside)
• Replace the scrubber assembly into its clips on the rear panel.
• Reconnect the plastic tubing to the fitting of the particle filter.
• Adjust the scrubber cartridge such that it does not protrude above or below the
analyzer in case the instrument is mounted in a rack. If necessary, squeeze the clips
for a tighter grip on the cartridge.
M9110EH Rev 0 153