Teledyne 7120 - NDIR analyzer - Manual (Page 69)

5 Maintenance Model 7120
5-2 Teledyne Analytical Instruments
3. Insert a small flat-blade screwdriver into the slot in the receptacle
wall nearest the fuse and gently pry open the fuse receptacle. The
fuse holder will slide out. There are two fuses in use and are
visible in the clip.
4. Remove the bad fuse and replace it with a two 3 AGmm 1.0 A,
250 VAC, IEC time lag (T) fuse (P /N F9).
5. Replace the fuse holder into its receptacle, pushing in firmly until
it clicks.
5.1 Routine Maintenance
The 7100 should be inspected on a regular schedule to be determined
by the maintenance personnel. The system filter and analyzer
measurement cell should be maintained as required by the quality
of the sample.
Periodic calibration of the system will assure accurate analysis of the
sample gas and will also indicate the need for maintenance. A regular
calibration schedule should include recording of the zero and span pot values
for performance trends. Clogging of the sample system and other system
problems will usually show early symptoms during online analysis or during
calibration.
Problems with the system not due to the normal processing of the
sample are sometimes failures which must be corrected.
5.2 Filter
The system filter element (if included) should also be periodically
inspected. Replacement is recommended when the element begins to restrict
sample flow or upon visual inspection looks clogged and dirty.
NOTE: Although not normally included on basic Model 7120
analyzers, input protection filtering is always recom-
mended. Refer to the system piping schematic for recom-
mended hook-up.