Cleaning Or Changing Critical Flow Orifices; Figure 9-7: Critical Flow Orifice Assembly - Teledyne 200E Instruction Manual

Model 200E Instruction Manual
• Reassemble in proper order and re-attach the reaction cell to the sensor housing.
Reconnect pneumatics and heater connections, then re-attach the pneumatic sensor
assembly and the cleaning procedure is complete.
• After cleaning the reaction cell, it is also recommended to exchange the ozone
supply air filter chemical as described in Section 9.3.3.
• After cleaning, the analyzer span response may drop 10 - 15% in the first 10 days
as the reaction cell window conditions. This is normal and does not require another
cleaning.

9.3.10. Cleaning or Changing Critical Flow Orifices

There are several critical flow orifices installed in the M200E, Figure 9-6 shows one of the
two most important orifice assemblies, located on the reaction cell. Refer to Section 10.2.9
for a detailed description on functionality and locations. Despite the fact that these flow
restrictors are protected by sintered stainless steel filters, they can, on occasion, clog up,
particularly if the instrument is operated without sample filter or in an environment with
very fine, sub-micron particle-size dust.
The M200E introduces an orifice holder that makes changing the orifice very easy. In fact, it
is recommended to keep spare orifice holder assemblies at hand to minimize downtime and
swap orifices in a matter of a few minutes. Appendix B lists several complete spare part kits
for this purpose. To clean or replace a critical flow orifice, do the following:
044100102 Rev A

Figure 9-7: Critical Flow Orifice Assembly

Instrument Maintenance
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