Agilent Technologies HP 5890 II Plus Series, Manual

Page: 35 / 53

Installation
Connecting supply gases
34
Connection between the valve and liquid N
1
supply must be insulated
and as short as possible so liquid, rather than gas, is supplied to the inlet
valve. Foam tubing used for refrigeration and air•conditioninglines is
suitable insulation. Insulation should cover as much as possible.
Caution
Liquid N
2
cylinders are equipped with a safety relief valve to prevent
excess pressure. Release pressure is set by the supplier. The pressure
setting should be in the range 138 to 207 kPa (20 to 30 psi) for proper
operation. Lower pressures may cause inadequate cooling; high
pressures may cause uncontrolled cooling, damaging oven and
contents.
Connect tubing to the liquid N
1
supply using a suitable adapter.
Gas supply checklist
To connect lines to the appropriate gas supply(ies), you should have
completed the following steps:
1. Ensure all gas supplies are off prior to connection and that all
unconnected fittings are capped.
2. Route gas supply tubing along the oven wall (using the wall slots
provided) to the appropriate mass flow controller or flow manifold
block.
3. Select the appropriate tube connections for gas supplies and make
connections.
4. Pressurize the system.
5. Compensate for pressure differences between the source and the
instrument.
6. Leak test each connection.
7. Install cryogenic cooling gas supply (if applicable).