Thermo Scientific 10519, Instruction Manual

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Chapter 2 Installation
2-6
The sonic orifice uses a quartz wool to prevent sample particulates to enter the critical flow
passage. The quartz wool acts as a particulate filter (Figure 2-5). The quartz wool is
periodically changed every three months for continuous monitoring. The quartz wool is
placed into the end of the orifice against a glass frit. The glass critical orifice is attached to
the dilution nozzle/heat exchanger section with a graphite ferrule and nut. The mantel
section is carefully threaded onto the dilution nozzle/heat exchanger.
Figure 2-5 . Sonic Orifice Assembly
CAUTION: This is a very fine threaded section and requires anti-seize
compound on the threads since this section will be located in the zone of the
source. Also, caution should be observed when unthreading this unit to prevent
breaking the glass critical orifice.