POPULAR CONFIGURATION GCs
Multiple Gas Analyzer #2
General Operating Procedure
2. DamageordestructionoftheTCDfilamentswilloccurifcurrentisappliedintheabsenceofflowingcarrier
gas. ALWAYSverify thatcarriergascanbedetectedexiting theTCDcarriergasoutletBEFORE turningON
theTCDcurrent. Labelledfor identification, theTCDcarriergasoutlet tubing is located inside thecolumn
oven. Place theendof the tubing in liquidandobserve. If therearenobubblesexiting the tube, there isaflow
problem. DONOTturnONtheTCDcurrentifcarriergasflowisnotdetectable. Afilamentprotectioncircuit
prevents filament damage by shuttingOFF the TCD
currentwhen thecolumnheadpressure isbelow3psi.
Because this protect circuit cannot prevent filament
damageunderallcircumstances,any lackofcarriergas
flowshouldbecorrectedbeforeproceeding. NEVER
turnbothcarrier#1andcarrier#2OFFat thesame time.
Pleasesee theTCDmanualsectionformore information
about thedetector.
3. Set thevalveoven temperature to90
o
Cusing the
trimpoton the topedgeof theGCfrontcontrolpanel.
5. Set thecolumnoven temperatureprogram inPeakSimpleasfollows. (This isanexample;youranalysis
mayrequireadifferent temperatureprogram.)
Initial
Hold Ramp Final
50.00 3.00 20.00 220.00
220.00 25.00 0.00 220.00
4. Turn the TCD current ON to LOW. If present,
ignite theFID/methanizerandset the temperature to
380
o
C. Ifpresent, turnON theHIDcurrent.
Use the trimpot directlyabove the “VALVE” zone to
setoradjust thevalveoven temperature.
TheTCD carrier gasoutlet tubing is located inside the
column oven. If there is also an FID detector on your
MG#2, theTCDcarriergasoutlet tubing isconnected to
theFID inlet bulkhead in the columnovenwall. If your
MG#2 has a TCD only, the end tubing will be on the
outsideof thecolumnoven, on thedetector side.
1. Set thegascylinderpressure15-20psihigher than the
headpressure(heliumcarrier). Thecarrierheadpressure
used togenerate the testchromatogramsat the factory is
printedon theright-handsideofyourGC.Verify thatwith
carriergas turnedoffat thecylinder, that theactualGC
pressure readsZERO.
