TheSRIMudloggerGC configuration canbe
operated
without
compressed cylinder
gases by using theSRI H2-40Hydrogen
generator and thebuilt-inair compressor.
Since theMudloggerGCuses twoFIDde-
tectors the total amount of hydrogen required
is close to the40ml/minute capacity of the
H2 generator. If hydrogen is also used as
carrier gas theH2-40makes just enoughgas
to run theMudlogger GC, but caremust be
taken tooptimize thegas flows so that no
more than40ml/minute is consumed.
Thephotos at right show theH2-40 con-
nected toaMudloggerGC. Note that the
hydrogen is split threeways for carrier gas,
FID#1 combustionandFID#2 combustion
hydrogen.
On theGC, theCarrier gas is set to3psi, the
FID#1 combustionH2 is set to 3psi and the
FID#2 ( theFIDwhichmeasures total hydro-
carbons ) combustionH2 is set to18psi.
TheFID#1 combustionH2 is set to3psi be-
cause the carrier gas is also hydrogen so the
total amount of hydrogengoing toFID#1 is
the sumof the carrier plus the combustion
H2.
A typical natural gas chromatogram is shown
at right. Because theamount of H2 is lim-
ited to40ml/minute, theanalysis time ( 5
min ) is a little longer than it would be if the
carrier gas flow couldbe increased. Unfor-
tunately the carrier flowmust be limited so
theH2-40 cyclesonandoff. Usea stop-
watch tomeasure the amount of time the
H2-40 spends generatinghydrogen com-
pared to the time it spends resting. This
ratio shouldbeat least 4 to1. So if theH2-
40 spends 4minutesmakinggas it should
rest for 1minute.
Operationof theSRIMudloggerGC
with theH2-40Hydrogen generator
