BUCHI DuMaster D-480 - Manual (Page 232)

Operation Manual D-480 ©BÜCH Labortechnik AG
8 - Maintaining the instrument 232
 Close the front door.
Phase 2: Conditioning the reaction tube, getting the instrument ready to measure
Proceed as follows:
 Close the "Replace part" dialog in the operating software. To do so, click Finish in the "Replace
part" dialog. By doing so, the gas will be automatically turned on. and the atmospheric nitrogen is
removed by flushing with CO
2
for five minutes.
 Reduce CO
2
pressure at the delivery point until the CO
2
flow meter displays "Flow CO2" on
screen at approx. 400 ml/min.
 Wait the required conditioning time. See table of "conditioning rules" in Conditioning newly
installed tubes (on page 172).
 Close the ground-in clamp on the reduction tube.
 Set CO
2
intake pressure on the cylinder manometer so that...
 ... the "Pressure" display shows 1200 - 1250 mbar on screen.
 ... the measuring gas flow meter "MFC-TCD" displays 650 ml/min on screen.
 ... the CO
2
flow meter "Flow CO2" displays approx. 650 ml/min on screen.
 Decide:
 If approximately the same flow and pressure values as prior to maintenance work are
displayed: The instrument is ready to measure again.
 If 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 for further conditioning when the leak test is successful.
To be observed after maintenance
If you have performed maintenance work that has a defined maintenance interval, you must manually
reset the "Status" field to zero on the "Maintenance intervals" dialog (accessible via Options >
Maintenance > Intervals. See Defining maintenance intervals in the software (on page 170).