Thermo Scientific EA IsoLink IRMS System Operating Manual page 69

• Pyrolysis — The carrier gas flow through the pyrolysis reactor is lower than in the combustion
mode. It is commonly set to 100 mL/min. The flow through the separation column is the same as
in combustion mode: 50 ml/min if the carrier gas flow is 100 mL/min. Unlike in combustion
mode the carrier flow is not reduced during the analysis. V1 is open until acquisition is completed.
He saving is achieved by using the split flow for purge just as in combustion mode.
To avoid high pressure on the chromatographic column in the combustion system the reference
flow (50 – 150 mL/min) is split using EV3 and reunited after the chromatographic column.
Thus V3 is also open all the time.
Setting Different Flows and Switching Times
It is possible to change the default settings for switching the He Save Mode. Click on the button and
choose the tab "HeM".
Here you can define when the He Save Mode is switched on and how high the carrier flow shall be
during the He Save Mode.
Note Changing the values will have influence on your analytical results. All instructions in this
manual are based on the default settings (100s, 50 mL/min).
Note The flow during He Save Mode must be identical to the split flow through the GC column
during Analysis Mode. This is mandatory to maintain a constant TCD signal.
Thermo Scientific EA IsoLink IRMS System for CNSOH Operating Manual
2
Analytical Principles
Pneumatic Circuit
41