GC INJECTORS
Model 8640 20-Vial Integrated Liquid Autosampler
Changing the Needle
1. Toremove theneedle, loosen the thumbscrewon the topof thewastediverterand the thumbscrewon the
needleguideclosest to thesyringebarrel. Loosenandremove the twobushingretainers. Carefully liftout the
needle, the twoTeflon
TM
bushingsand thewastedivertervalve together. Youwillhave topush thewaste
divertervalveoutof theneedleguide, andangle theneedle tipout through theslot in thesideof thewaste
diverterneedleguideasyoupull theneedlefrom thesyringebarrel.
2. Slide thewastediverter valve and the twoTeflon
TM
bushingsofftheoldneedleandontothereplacementneedle.
3. Place theneedle into the thumbscrewneedleguideand
thesyringebarrel,andcarefullyangle theneedlewith the
bushingsandwastedivertervalveintoplace,usingtheslot
inthewastediverterneedleguidetogetthetipoftheneedle
intoalignmentwiththesyringebarrel.
4. Position the twobushings in theircradles, thenreplace
andtightenthebushingretainers. Tightenthethumbscrews
on theneedleguideandwastediverter.
5. Adjust thesample injectionvolumeby looseningboth
hex-head locknuts, then turning theknurled thumbscrew
toachieve thedesiredvolume. Tighten the locknuts.
Loosen these2
thumbscrews
Loosenand remove these2bushing
retainers, then remove the2bushings
In thecourseof normal operation, the8640 sample injectionneedlemaybecomebent or otherwise
damaged and require
replacing. Make sure the
syringemechanism isfully
retracted before starting;
thisisthedefaultpositionto
which itshouldreturnafter
asampleinjectionsequence.
Replacement needles
areavailable fromCentral
Instruments under part
number 502743. Syringe
barrel andneedle sets are
availableunderpartnumber
503188. Call Central
Instrumentsat:
225-261-1917
Orwrite to:
P.O.Box337
GreenwellSprings,LA70739
USA.
Sample tray
Sampleprobe
assembly
Needle
Sampleout towaste
Needle guide with
wastedivertervalveand
knurled thumbscrew
Teflon
TM
bushings
Wastebottle
Samplesizenut (knurled)
Locknuts (2)
