Agilent Technologies 7000 Triple Quadrupole GC/MS, Maintenance Manual

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Introduction
1
Troubleshooting and Maintenance Manual 15
Hydrogen Safety
Hydrogen is a commonly used GC carrier gas. Hydrogen is potentially
explosive and has other dangerous characteristics.
• Hydrogen is combustible over a wide range of concentrations. At
atmospheric pressure, hydrogen is combustible at concentrations from 4%
to 74.2% by volume.
• Hydrogen has the highest burning velocity of any gas.
• Hydrogen has a very low ignition energy.
• Hydrogen that is allowed to expand rapidly from high pressure can
self-ignite.
• Hydrogen burns with a nonluminous flame, which can be invisible under
bright light.
Dangers unique to GC/MS operation
Hydrogen presents a number of dangers. Some are general, others are unique
to GC or GC/MS operation. Dangers include, but are not limited to:
• Combustion of leaking hydrogen
• Combustion due to rapid expansion of hydrogen from a high-pressure
cylinder
WA R N I N G
The use of hydrogen as a GC carrier gas is potentially dangerous.
WA R N I N G
When using hydrogen (H
2
) as the carrier gas or fuel gas, be aware that hydrogen
gas can flow into the GC oven and create an explosion hazard. Therefore, be sure
that the hydrogen supply is turned off until all connections are made and ensure that
the inlet and detector column fittings are either connected to a column or capped at
all times when hydrogen gas is supplied to the instrument.
Hydrogen is flammable. Leaks, when confined in an enclosed space, may create a
fire or explosion hazard. In any application using hydrogen, leak test all
connections, lines, and valves before operating the instrument. Always turn off the
hydrogen supply at its source before working on the instrument.