I
NSTALLATION
GC Installation
CP-3800 GC Getting Started Manual
13
Select Gases The following gases are commonly used in Gas Chromatography for the
following functions. Note that the recommended purity for carrier make-up
and detector fuel gases is 99.999%. In addition, the use of gas filters to
remove hydrocarbons, oxygen, and water from carrier gases is
recommended.
Gas
Function
He, N
2
, H
2
, Ar, Ar/CH
4
Carrier gas
H
2
, Air Detector fuel gases
He, N
2
,
Ar/CH
4
Make-up gas for capillary column use
Air AutoSampler operation
LN
2
, LCO
2
Cryogenics
Install Gas
Regulators
and Set
Pressures
Carrier gas, air and H
2
supplied from cylinders or manifolds should have a
two-stage regulator having a zero to 100 psi low-pressure stage. Set
cylinder regulator pressure to match the GC gas inlet pressures, listed
below:
Gas Inlet
Pressure
Carrier gas 80 psi
Make-up 80 psi
Air 60 psi
H
2
40 psi
Connect
Gases
Follow the steps below to connect gas supplies to your 3800 GC:
1 Cut required lengths of heat-cleaned 1/8
″
copper tubing for the
carrier and fuel gas plumbing. Clean the ends of the tubing with a
metal file.
2 Slide a 1/8
″
Swagelok
nut, back ferrule, and front ferrule over one
end of the copper tubing and attach to the outlet fitting on the
cylinder regulator.
3 Push the copper tubing into the outlet fitting as far as it will go, then
pull back very slightly and tighten 3/4-turn past finger-tight with a
7/16
″
wrench.
4 Slide a 1/8
″
Swagelok nut, back ferrule, and front ferrule over the
other end of the copper tubing and connect it to the corresponding
gas inlet on the GC rear panel.
