Buchi DuMaster D-480, Руководство по эксплуатации

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Operating instructions DuMaster D-480 ©BÜCHI Labortechnik AG
8 - Maintaining the instrument 170
"Preparing the instrument: Gas pressure"
Proceed as follows:

Shut off gas supply. Open the "Replace part" dialog in the operating software by selecting
Options > Maintenance > Replace Part
.

Wait for pressure drop without pressing any buttons until the message "Part can now be
replaced." is displayed and the
Finish
button becomes accessible.

Pressure has been reduced when the following displays show "0" on screen:

"MFC CO2".

"Flow CO2".

"Pressure".

The instrument is now ready for replacement of the part.
Follow-up instrument preparation: Gas pressure / gas-tightness
Proceed as follows:

Close the "Replace part" dialog in the operating software. To do so, click
Finish
in the "Replace
part" dialog. This automatically switches on the gas again and the atmospheric nitrogen is
removed by flushing with CO
2
.

Decide:
If...

... approximately the same flow and pressure values as prior to maintenance work are
displayed: The instrument is ready to measure again.

... distinctly different flow and pressure values to those displayed prior to maintenance work
are displayed: Perform a leak test. See Performing a leak test. The instrument is only ready
to measure when the leak test is successful.
Conditioning newly installed tubes
Purpose of conditioning
Newly installed tubes must be conditioned:

to remove nitrogen from air inclusions in the filling material

to remove moisture from the tube fillings

to remove contaminations

Reductor ready for meaurement
Without conditioning, analysis results would be distorted.
Types of conditioning
There are the following types of conditioning new tubes:

Flushing tubes to remove nitrogen from air inclusions in the filling material. The following are
flushed:

Large drying tube

Small drying tube

Baking out tubes to remove moisture and contaminations from the tube fillings. The following are
baked out:

Combustion tube

Post combustion tube

Reductor