Yokogawa In-Situ Gas Analyzer TDLS200 - Manual (Page 98)

7-2
IM 11Y01B01-01E-A 6th Edition :Feb 13, 2013-00
<7. ROUTINE MAINTENANCE>
Figure 57 - Window Cleaning
TDLS200 TDL Analyzer Instruction Manual V2.1
Page 88 of 131 - 88 -
Window surface to
be cleaned
If the windows are contaminated they may be cleaned using the following procedure:
• Remove analyzer from process (isolate, etc. if necessary)
• Use a clean, dry instrument air or nitrogen pressure supply to first blow off any particulate
matter.
• Using warm water and mild soap detergent, gently clean the window surface with a soft,
non-abrasive cloth.
• If the deposits do not come off then use a small amount of IPA (Isopropyl Alcohol) and a
soft, non-abrasive cloth.
• Use the same clean, dry instrument air or nitrogen pressure supply to blow dry the surface.
• Carefully check the entire surface of the window from different angles to ensure it is
thoroughly cleaned and ready for service.
• If the window does not appear to clean up well, then replace the window assembly with a
new one.
• If the window appears to have an etched surface then it has probably been contaminated
with HF or other similar corrosive gas.
Figure 32 - Window Cleaning
Figure 56 - Window Replacement
TDLS200 TDL Analyzer Instruction Manual V2.1
Page 89 of 131 - 89 -
Figure 33 - Window Replacement
5.1.2 Replacing Windows:
If it has been determined that a window required replacement, then the following should be
performed:
• Shut down the analyzer and remove power, thus ensuring the laser if OFF.
• Remove Launch or Detect (as appropriate) from the process interface by removing the one
fixed hole fastener (5/32” Allen Wrench), loosening the remaining three fasteners and then
twisting and pull off the unit.
• Remove the four retaining screws (3/32” Allen Wrench, T-Handle) and lock washers from
the window holder recessed inside the quick connect body.
• Remove the window that requires replacement.
• Ensure the new replacement window is of the same specification as the window being
removed. Standard Windows are 0.25” Thick wedged, BK-7 borosilicate crown glass
mounted in stainless steel retaining ring.
• The window holder assemblies can only be installed in one way by virtue of the mounting
hole placement.
• Ensure a new O-Ring (of same specification) is installed at the same time. Viton is the
standard material however, certain applications may require other materials – check original
specifications.
• With the new O-Ring in position, carefully locate the new window holder in place with the
smooth glass surface against the O-Ring.
• Carefully tighten all four screws (ensuring the lock washers are in place) using a T-handle
wrench. Keep tightening all the fasteners in turn by ¼ turns thus ensuring an even torque
loading.
• Hand tighten the screws until they are very firmly tightened (a T handle wrench as shown
below will torque its own shaft by about ¼ turn when the screws are fastened securely).
Offset screw position
for window
O-ring correctly
seated in position
O- ring correctly
seated in position