Series 4 Operating Manual - Nebula Issue 1.00
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7 Routine Maintenance
7.1
Introduction
The analyser requires little routine maintenance to keep it in good working order.
If the analyser is used infrequently, check the filter and Zero/Span calibration every time it is
used.
If the analyser is used continuously, check the filter and Zero/Span calibration once per week
or as experience dictates.
The filter may need to be checked at different intervals depending on the particulate content
of the sample gas.
Zero/span calibration may need to be checked at different intervals depending on the local
variations in ambient temperature and/or atmospheric pressure.
7.2
Sample Filter
Signal recommends and supplies PTFE filters (Part number FILT/023) for use as internal
Sample filter in all measurement instruments. These PTFE filters may be cleaned and re-used.
Glass fibre filters are not recommended for use in our heated analysers. They can be damaged
during installation into the heated manifold and fibres can become detached and block critical
sample paths.
Removal/Replacement
Before filter removal, ensure that the Sample gas line has been shut off using an external
valve, or that the process has been paused to allow for safe servicing of the analyser.
•
Disconnect the sample gas line from the back of the instrument.
•
The filter is immediately behind the pipe fitting. The pipe fitting and filter cap are
removed as a single item using a special tool. Identify the filter extraction tool
(MC/318011), supplied in the accessory kit. Using the filter extraction tool, release
the filter cap by rotating ¼ turn anti-clockwise.
•
Reverse the filter extraction tool and screw it onto the pipe fitting.
•
Withdraw the housing, taking care not to touch the hot surfaces.
•
The filter element will be found protruding from the cap. It will quickly cool and may
be removed by hand. Dirty filters can contain corrosive compounds. Use gloves.
CAUTION
If the analyser has been switched on, the filter housing may be too hot to touch. The
filter replacement tool provides a method for changing hot filter elements.
Dirty Filters may contain corrosive compounds. Use gloves. Obey local safety
measures.
