BUCHI DuMaster D-480 - Manual (Page 143)

Operation Manual D-480 ©BÜCH Labortechnik AG
7 - Using the instrument 143
Checklist
Go through the following list:
 Were the results of a blank value determination OK?
 Were the results of the conditioning sample measurement OK?
 Have you processed a series of measurements with daily factor samples?
 Are the operating gases on?
 Are the furnaces at setpoint temperature?
 Combustion tube: 950 °C
 Post combustion tube: 800 °C
 Reduction tube: 815 °C
 Is pressure OK?
 Display on the PC "Press. Input": 1200 - 1250 mbar
 Display on the PC "Press. Output": 800 - 1000 mbar
 Is the flow meter display OK?
 Measuring gas flow meter on the PC "MFC CO2": 650 ml/min
 CO
2
flow meter on the PC "Flow CO2": approx. 650 ml/min
 O
2
flow meter on the PC during O
2
dosing "MFC O2": as selected in the method
 Does the desiccant still have sufficient capacity?
 At least the last third should still be unused.
 Have the maintenance intervals been observed? Check:
 The drying tube.
 The reduction tube.
 The ash crucible.
 Is the detector signal small and stable?
 Is the proper method allocated to the respective samples?
 Is the carousel loaded?
If you answer yes to all of the above, you can start measuring real samples.
Types of blank value determination and their settings
Background
Blank value determination can be used for various purposes and is therefore performed in different
ways. The different types of blank value determination are described below with an explanation of the
respective settings.
Degree of gas tightness (N blank value)
This blank value determination is performed as a routine task. It makes sense after gas cylinder
replacement and after maintenance work.
 The blank value determination is performed without a sample.
 Use the method "Blank with O2".