SRS Labs QMS 100 Series, Руководство пользователя

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5-18 Cleaning
SRS QMS Gas Analyzer
grit down to 12000 until the metal surface has a fine polished appearance. Warning: Do not
remove excessive material from the surface of the precision-ground rods.
14. After all metal surfaces have been polished, they must be cleaned to remove all the abrasive
compound from their surface. Begin by placing the rods in a beaker with a 1:4 solution of “Mr.
Clean” detergent in water. (Note: if Mr Clean is not available, use a good quality cleaning
compound that leaves no residue after rinsing) Place the beaker in the ultrasound cleaner and
agitate for 30 minutes. Decant off the cleaning solution, and repeat the above agitation with 4 to
5 consecutive washes with distilled water to remove the cleaning solvent. Decant off all the
water from the parts, and rinse all parts with acetone and then with Methanol (Use the ultrasonic
cleaner for best results). Following the rinses, blow dry the rods with filtered dry nitrogen and
then bake them out in an oven at 150
°
C for one hour. Warning: After the parts have been
cleaned and baked out, they should only be handled wearing powder-free gloves.
15. Head Reassembly: Only a rough outline of the complete reassembly of the probe is presented
here. Use the RGA Assembly Drawing of Chapter 9 and your own notes as a visual aid
during this process.
Begin by assembling the quadrupole mass filter. Loosely attach the cleaned rods to the alumina
spacers with the spring-loaded, perforated screws. Tighten the screws following the
systematic
procedure described next. Work on one spacer at a time, using a single, small turn of the
screwdriver on each screw. After a single round of eight screws, hold a spacer in each hand,
and slightly torque the assembly back and forth about its axis to make sure the rods are
comfortably seated on their positioning slots. Repeat this tightening procedure, one spacer at a
time, constantly checking the alignment, until the spring washers are completely compressed.
Once the quadrupole assembly is completed, mount the focus plate and the anode grid on it.
Use new e-clips to hold the two ionizer plates against the top alumina spacer, but do not install
any e-clips on the bottom grooves of the connection rods at this time. Next, mount the
quadrupole assembly on the exit plate of the feedthru flange and secure it in place tightening the
two connector screws and inserting an e-clip in the exit plate align rod groove. Insert the rest of
the rods in their correct locations and, while checking for the correct alignment of their grooves
and slots, tighten the rest of the feedthru connector screws. Once the rods are in place, attach
the two RF ribbon connectors to complete the quadrupole filter assembly.
If the RGA probe has a CDEM, mount the multiplier at this time. Adjust the HV connect rod as
needed, and tighten all the necessary screws (The threaded hole on the side slot of the rod lines
up with the CDEM Clamp hole, and the top groove should be correctly lined up with the edge
of the alumina spacer’s alignment hole.)
Install new bowed e-clips in all the grooves located above the alignment holes of the bottom
alumina spacer. The clips hold the filter tightly against the exit plate. Finally, install the filament
and the repeller cage.