Knauer 4000 MiD, Инструкция по эксплуатации

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48 Troubleshooting
4000 MiD® Instructions, V6695
Symptom Possible Cause Remedy
No signal; spray current es-
tablished and unchanged.
Ion optics have the
wrong voltages.
With the MiD on, load
one of the four default
tune files (see chapter 7
on page 30).
Detector is switched off. With the MiD switched
on and pumped down,
check that the detector is
switched on and has the
correct voltage applied
to the Horn (see chapter
7 on page 30).
Pressures are not at the
operating values.
With the MiD switched
on and pumped down,
check the pressures in
the ion guide and the
analytical chambers are
at operating values.
The vac-chip is clogged. Replace the vac-chip (see
chapter 8.2 on page 33).
No signal; no spray current. No sample flow Check liquid connections
and sample flow from the
syringe pump/LC to the
spraychip assembly.
Capillary tip may be
clogged.
Change the spraychip
200 (see chapter 8.2 on
page 33).
A voltage cannot be
applied to the spraychip
assembly because the
interlock is engaged.
Make sure the front door
is fully closed. Check the
interlock status symbol.
Drop in ion signal to zero
counts; capillary current
increases.
A droplet has formed
inside the spraychip
assembly
Ensure that no sample
is flowing through the
system. Increase the flow
rate of the nebuliser gas
to 5 L/min. Enable the
high-voltage supply and
increase the capillary
voltage. Run the system
under these conditions
for 15 minutes. Use a hig-
her nebuliser flow rate if
the problem persists.
Replace the spraychip
200 (see chapter 8.2 on
page 33).
Severe drop in TIC back-
ground accompanied with
no signal for late eluting
peaks in an HPLC reverse
gradient chromatograph.
The vac-chip is clogged. Replace the vac-chip
(see chapter 8.2 on page
33)..