Teledyne 9110T - Nitrogen Oxides Analyzer - Manual (Page 274)

Model 9110T NOx Analyzer Troubleshooting & Service
Teledyne Analytical Instruments 274
2. If the actual flow is low or zero, check if the pump operates properly. The
RCEL pressure should be below 10 in-Hg-A at sea level.
 If it is above 10”, rebuild the pump (Section 11.3.4.1). Check the spare parts list
in Appendix B on how to order pump rebuild kits.
3. Check if the particle filter is clogged.
 Briefly remove the particle filter to see if this improves the flow.
 Be very cautious when handling the Perma Pure dryer fittings (see Section
11.3.2 on proper handling instructions).
 If the filter is clogged, replace it with a new unit.
 If taking off this filter does not solve the problem, continue to the next step.
 Do not leave the Perma Pure dryer without filter for more than a few seconds,
as you may draw in dust, which will reduce the performance of the dryer.
4. A leak between the flow meter and the reaction cell (where the flow-
determining critical orifice is located) may cause a low flow (the system
draws in ambient air through a leak after the flow meter).
 Check for leaks as described in Section 11.3.12.
 Repair the leaking fitting, line or valve and re-check.
5. The most likely cause for zero or low ozone flow is a clogged critical flow
orifice or sintered filter within the orifice assembly.
 The orifice that sets the ozone flow is located on the reaction cell.
 Check the actual ozone flow by disconnecting the tube from the reaction cell
and measuring the flow going into the cell.
 If this flow is correct (~80 cm³/min), the orifice works properly.
 If this flow is low, replace the sintered filter.
 The orifice holder assembly allows a quick and easy replacement of the filter
(see Section 11.3.5 and on for replacement procedures).
 Appendix B lists a spare part kit with a complete orifice assembly that allows a
quick replacement with minimum instrument down-time.
12.4.1.3. High Flow
Flows that are significantly higher than the allowed operating range (typically ±10-11% of the nominal
flow) should not occur in the 9110T unless a pressurized sample, zero or span gas is supplied to the inlet
ports.
 Ensure to vent excess pressure and flow just before the analyzer inlet ports.