Inficon HAPSITE ER - Page 415

14 - 4
HAPSITE ER Operating Manual
Mass Defect . . . . . . . . . . . . . . . . . . The effect on a mass spectrum of the
difference between the atomic weight of a
compound or fragment and a whole number.
Mass spectrum . . . . . . . . . . . . . . . . A display of the amount of each mass
fragment present at the specific time, plotted
as amplitude vs. molecular weight.
MDP . . . . . . . . . . . . . . . . . . . . . . . . . Molecular dispersion pump.
Membrane Isolation Valve . . . . . . . The valve which supports the Mass
Spectrometer’s inlet membrane and (when
closed) interrupts the flow of analyte from the
membrane into the Mass Spectrometer.
Method. . . . . . . . . . . . . . . . . . . . . . . A set of instructions for a function of the
HAPSITE.
Molecular Weight . . . . . . . . . . . . . . The amu representation of the total number
of protons and neutrons in a specified
molecule.
MS . . . . . . . . . . . . . . . . . . . . . . . . . . Mass Spectrometer
ms . . . . . . . . . . . . . . . . . . . . . . . . . . milliseconds
MSDS . . . . . . . . . . . . . . . . . . . . . . . . Material Safety Data Sheet
Multiplier Voltage . . . . . . . . . . . . . . The voltage applied to the multiplier in the
mass spectrometer, which directly effects the
amplitude of signal and background noise.
NEG . . . . . . . . . . . . . . . . . . . . . . . . . Non-evaporative getter as a vacuum source
NIST Library . . . . . . . . . . . . . . . . . . NIST stands for National Institute of
Standards and Technology Mass Spectral
Library. This is a library of spectra of
compounds which can be searched to
tentatively identify unknown compounds.
Noise Check . . . . . . . . . . . . . . . . . . An option in the Tune program which checks
the system for background noise. The results
of the noise check are used to discriminate
against baseline noise during analysis.
Pascal (pa) . . . . . . . . . . . . . . . . . . . Unit of pressure, equal to 1 dyne per cm
2
.
Equivalent to 7.5 x 10
-3
Torr and
1.45 x 10
-4
PSI.
PEEK . . . . . . . . . . . . . . . . . . . . . . . . A contamination resistant material used for a
number of fittings in the HAPSITE ER.