BUCHI DuMaster D-480 - Manual (Page 174)

Operation Manual D-480 ©BÜCH Labortechnik AG
8 - Maintaining the instrument 174
Safety instruction
Strictly observe the safety instruction "Baking out combustion/reduction tube" under Warning notes
during operation (on page 24).
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 carrier gas for five minutes.
 Reduce the carrier gas pressure at the delivery point until the CO
2
flow meter displays approx.
400 ml/min "Flow CO2" on the screen.
 Wait the required conditioning time. Refer to the above table "Conditioning for combustion tube
and reduction tube".
 Close all open ends of the reaction tubes again.
 Set the carrier gas intake pressure on the cylinder manometer so that...
 ... the "Pressure" display shows 1200 - 1250 mbar on screen.
 ... the measuring gas flow meter "MFC CO2" displays 650 ml/min on screen.
 the CO
2
flow meter "Flow CO2" displays approx. 650 ml/min on screen.
 Decide:
If the operating software status view displays...
 ... 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 (on page 242). The
instrument is only ready to measure when the leak test is successful.