5Methodsï€
Operation Manual 99
When the valve is set to On, the front column is selected. When the valve is set to Off, the back
column is selected
Use a run table entry to ensure that the valve is in the Off state between runs.
Sampling valve
If a valve is configured as a sampling valve, it starts a run automatically when it is switched to
the Inject position. This can be done by a subsequence or clock table entry. You may have two
gas sampling valves installed.
Sampling valves have two positions:
Load position The loop (external for gas sampling, internal for liquid sampling) is flushed with
a stream of the sample gas. The column is flushed with carrier gas.
Inject position The filled loop is inserted into the carrier gas stream. The sample is flushed
onto the column. The run starts automatically.
Carrier gas may be provided by an (optional) auxiliary gas channel. To do this, configure the
column and specify an Aux # channel as the inlet. The channel then becomes programmable
with four operating modes.
The gas sampling valve control parameters are:
Front column
Back column
To detector
From inlet orï€
sampling valve
ON
OFF
Carrier in
To column
Sample in
Sample out
LOAD position INJECT position
Loop