HP 5973 MSD Hardware Manual page 118

Index
R
Reagent gas
ammonia, using, 65
carbon dioxide, using for NCI buffer gas, 66
CI theory overview, 22
cleaning supply tubing, 102
delay in turning on, 18
isobutane, using, 65
no negative ions, 30
plumb methane to Gas A, 16
plumbing into the CI interface, 20
purity specifications, 10
specifications, 10
using other reagent gases, 64
Reagent gas flow control module, 16
Gas A, always methane, 16
Gas Off, 16
isolation valve, 17
mass flow controller, 16
operating, 61
schematic, 18
state diagram, 19, 61
VCR fittings, 16
Reagent gas, regulators, 10
Repeller, CI, 14
S
Sensitivity
PCI affected by reagent ion background, 24
specifications, 9
verifying NCI performance, 60
verifying PCI performance, 59
Sequencing, not appropriate for CI methods using
different reagent gases or gas flows, 50
Shutdown. See Venting
Specifications
reagent gas purity, 10
sensitivity, 9
Startup
See also Pumpdown
118
methane pre-tune showing acceptable levels of
air and water, 55
setting up methane flow, 54
setting up the software for CI operation, 52
too much air and water, 55
State diagram, reagent gas flow control module,
19, 61
Switching
from CI to EI operating mode, 44
from EI to CI operating mode, 45
Symptoms of malfunctions
can not complete autotune, 90
excessive noise or low signal-to-noise ratio, 84
high electron multiplier voltage, 89
high pressure with reagent gas flow, 76
large peak at m/z 19, 85
no or low PFDTD signal, but reagent ions are
normal, 83
no or low reagent gas signal, 81
no peaks, 79
peak at m/z 32, 86
peak widths are unstable, 91
poor vacuum without reagent gas flow, 75
pressure does not change when reagent gas
flow is changed, 77
pressure-related symptoms, overview, 74
reagent gas ion ratio is difficult to adjust or un-
stable, 88
signal-related symptoms, overview, 78
tuning-related symptoms overview, 87