Bruker BPHG 90 - Operation of the BPHG 90

Operation
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7 Operation
TheBPHG90hasbeendesignedtooperateinalargelyautomaticmanner.Theuserhas
accesstodifferentmodesofoperationviaatouchpanelatthefrontoftheinstrument.The
touchpanelpresentstheuserwithinformationonoperationalparametersviaanumberof
screens.A typical screen layoutwill present a titlebar at the topof the screen, possibly
some operational parameters in the main field and some buttons for control over the
operation (see the next figure). Most operating screens feature a Settings button at the
lower right hand corner, giving access to instrument setup parameters (see the section
System Settings [}45].
Figure7.1:TouchScreenforInstrumentOperation
The main operating parameter of the BPHG 90 is the conversion temperature at which
ortho hydrogen is converted to parahydrogen. This temperature determines the yield of
parahydrogen(seethenextfigure).
Theinstrumentisdesignedtooperatebetween36and40K,producingH
2
gaswithmore
than85%parahydrogen.Theconversiontemperatureisauseradjustableparameter(see
thesectionAdjustable Parameters [}46]).
Figure7.2:ParahydrogenFractionFunctionofConversionTemperature