Teledyne 9110EH - Nitrogen Oxides Analyzer - Manual (Page 166)

Instrument Maintenance Model 9110EH Instruction Manual
locations). A pump rebuild kit is available from the factory. Appendix B of this manual lists
the part numbers of the pump rebuild kit. Instructions and diagrams are included in the kit.
A flow and leak check after rebuilding the sample pump is recommended. A span check and
re-calibration after this procedure is necessary as the response of the analyzer changes with
the RCEL pressure.
9.3.5. Changing the Pump and IZS Dust Filters
The exhaust air from the analyzer passes a small particle filter (DFU filter, part # FL3)
before entering the pump. When this particle filter becomes visibly dirty or the pressure
drop between SAMP and RCEL pressure increases significantly, it needs replacement in
order to prevent a large pressure drop with degraded analyzer performance.
• Power down the analyzer and pump.
• For internally mounted filters, skip the next two steps.
• For externally mounted filters on the pump housing, remove the analyzer exhaust
tube from the dust filter. Remove the particle filter from the pump. To do so, push
the white plastic ring into the fitting and pull the filter out of the fitting. If necessary,
use needle-nose pliers to pry the filter out of the fittings.
• Push a new filter into the pump fitting and make sure that the arrow on the filter
points towards the pump. Push the exhaust tubing onto the filter. Skip the next two
steps.
• For internally mounted filters at the inside rear panel, remove the chassis and locate
the filter between the vacuum manifold and the exhaust port fitting.
• Disconnect the clear tubing from the filter body and change the filter with the arrow
pointing against the gas flow. To remove the hose clamps, slide the two clamp ends
in opposite directions with a needle-nose pliers until the clamp comes apart.
Reconnect the tubing by using the same or new clamps and pushing tightening them
until a good seal is achieved.
• Restart the pump and clear any error warnings from the front panel display.
• After about 5 minutes, check the RCEL pressure reading and ensure that it is similar
to its value before changing the filter but less than 10 in-Hg-A.
A similar procedure applies to the same DFU particle filter that is used in the optional IZS
zero air scrubber assembly (Figure 9-4). To change this filter, simply disconnect the tube
and fitting from one end and remove the filter from the scrubber cartridge. Insert a new
filter and attach the tubing. Make sure that the embedded small arrow points in flow
direction.
9.3.6. Changing the IZS Permeation Tube
The optional IZS permeation tube that is filled with liquid NO
2
will be exhausted at some
point. The lifetime depends on the frequency of usage. To change this tube, purchase a
replacement and then
• Turn off the analyzer, unplug the power cord and remove the cover.
• Locate the IZS oven in the rear left of the analyzer.
• Remove the top layer of insulation if necessary.
152 M9110EH Rev 0