G
as chromatographs are shippedwith an instrument manual that includes information on the
pneumatics, electronics, computer hardware, and software installed in the new instrument. Unfortu-
nately, practical instruction on how to set up the gas chromatograph is one area that manymanuals do not
adequately cover. This guide presents the basic steps in setting up a newGC and useful information on
efficient and proper installation.
Index
Pre-Installation Instructions
2
Tools Required to Plumb theGC
2
Choosing the Proper GC Gases
3
Plumbing Gases to the GC
4
GC Gas Purification
8
LeakChecking
11
Instrument Logbook
11
Accessories
13
Educational Materials
26
Technical Service
28
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Pre-Installation Instructions
The first, and perhaps most important, rule of setting up a
newGC is to never throw anything away. All items are
grouped and labeled by the manufacturer. Keeping all parts
andmanuals togetherwill significantly reduce the chance of
misplacing critical documentation or spare parts. It is a good
idea to save the original box and packing materials in case the
GC must be returned to the manufacturer. The GC oven fan is
often bolted in place during transportation. The shipping bolt
must be removed from the back of the GC before turning on.
Next, determinewhere to install theGC. Allocate sufficient
bench space to permit installation of recorders, chromatogra-
phy data systems, autosamplers, and other GC equipment.
Two inches of space at the sides of the GC permits free air
circulation. Allow two feet of access space at the rear of the
GC for ease of service or future plumbing changes. Make the
installation site accessible to easily change traps and connect
gas lines.
Do not place the GC near a heating or air conditioning vent.
Variations in room temperature can affect the heated zones of
the GC. Chromatographically this problem is seen as reten-
tion time or baseline instability as the heating or AC units
cycle on and off. A constant room temperature and a site free
of hot or cold spots ensures optimum GC performance.
If the lab is not equipped with existing gas lines, set-up the
GC in a location near the gas source. Thiswillminimize the
amount of tubing required to plumb new instruments.
Continuous lengths of tubing between the cylinder andGC
manifold should be used to eliminate the possibility of fitting
leaks. If several GCs are being plumbed on the same carrier
gas line, connecting tees should be easily accessible for leak
checking and troubleshooting. (Do not hide tees or connec-
tors in a ceiling orwall. Thismakes it difficult to periodically
leak check!)
Determine the power requirements of theGC. If the power
requirement is less than 15 amps, the instrument may be
plugged into a 15 or 20 amp branch circuit. If the unit draws
15 amps or more, the GC power cord will have a 20 amp plug
and must be plugged into a 20 amp circuit (a 20 amp plug
looks similar to a standard three-prong plug, except that one
prong is turned at a right angle towards the other one). If the
plug on theGC doesn’t fit the outlets in your lab, consult a
qualified electrician before proceeding!
Generally, only oneGC should be plugged into a single 15 or
20 amp branch circuit. PluggingmultipleGCs into the same
electrical circuitmay cause the circuit breaker to trip on
occasions when two instruments are heating at the same time.
If possible, integrators or data systems should be plugged into
the same outlet or circuit as theGC fromwhich it is acquiring
data. Thiswill help to prevent ground loop currents from
developing between the two instruments, which can contrib-
ute to baseline noise. To further reduce electrical noise, use
high quality, shielded signal cables and keep the cables as
short as possible.
ToolsRequired toPlumb theGC
Once the instrument site is prepared, you are ready to
considerwhat gases are needed for theGC. Items necessary
to install a newGC include the following:
(See
pages 13-25 for catalog numbers.)
Wrenches (
1/8, l/4, 7/16, 9/16,
and 1/2-inch)
l
Phillips & flat head
screwdrivers
l
Solvent rinsed & heat treated stainless steel
tubing
l
Hoke plug valves
l
SS diaphragm regulators
l
MINICYL regulators
l
Ferrules
l
Tubing cutter
l
Tubing
bender
l
Reamer
l
Files
l
Replacement fittings
l
Adjustable
wrench
l
Teflon tape
l
Electronic leak detector
l
Brass tees
l
Swagelok nuts& ferrules
l
Pigtail fittings
l
Traps
l
Reducers
l
Septa
l
Deactivated sleeves
l
O-rings
l
Capillary column
2
2
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