The Zero Blast - Inficon Transpector MPH Operating Manual

Transpector MPH Operating Manual

3.4.2 The Zero Blast

When the mass filter is tuned to very low masses, the RF and DC voltages applied
to the rods approach zero. The quadrupole then ceases to act as a filter, and a
large current of unseparated ions is detected. This current is called the zero blast.
See Figure 3-4 on page 3-9.
The zero blast, present in all quadrupole-based sensors, can interfere with the
observation of masses 1 and 2 when significant quantities of higher-mass ions are
present. In some instruments, the magnitude of the zero blast is concealed by
preventing the voltages from reaching zero. With Transpector MPH, the zero blast
only produces parts-per-million interference to masses 1 and 2.
Figure 3-4 Zero blast
Zero Blast
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