Agilent Technologies 8860 User Manual

70 Agilent Gas Sample Selector for 8860 and 8890 User Manual
5 Maintenance and Troubleshooting
Sampling mode
Sampling mode
This mode is a pretreatment and is used for low concentration samples or
permanent gases. This mode unblocks the entire gas pipeline (for the bag version
the pump will also turn on in this mode), so the sample gas can purge any
remaining gas from the entire flow path.
When very low-concentration samples or permanent gases such as oxygen and
nitrogen are analyzed, the gas remaining in the selector system pipeline may affect
the sample results, especially when multiple gas bags are connected. For the
sample bag at the back of the injection sequence, a long wait time will cause the
small amount of gas remaining in the pipeline to continuously diffuse into the gas
bag, causing contamination of the sample. This mode helps minimize
this pollution.
Figure 19 Sampling mode for bag version.
1
5
3
7
1
2
3
4
5
6
Sample Loop
Carrier Gas
To C ol um n
Sample Out
Sample In
On/Off Valve
GC Valve 1
Needle Valve 2
MPV
Multi-Position Valve
Purge Valve
Gas
Bag
• GC Valve 1 – OFF
• Sample Valve – ON
• Purge Valve – OFF
•Pump –ON
Purge N
2
Needle Valve 1
n/
O
f
f
V
a
V
V
l
v
Pump
Assembly
Selector
Vent
Selector GC
GC
Selector
Sample Gas
Purge Gas
Carrier Gas

Agilent Technologies 8860 Specifications

General

Brand	Agilent Technologies
Model	8860
Category	Laboratory Equipment
Language	English