Troubleshooting - Hach AutoCAT 9000 Instruction Manual

Section 10
Problem
Symptom
Category
Display does
not show up or
Electrical
is too dark
Air bubbles
trapped in the
lines
Titrant leaks
Mechanical
Titrant doesn't
flow through
tubing
The titration is
very quick and
the resolution
of the titration
curve is too
low. The
Data
titration curve
Collection
is too noisy.
(w/o Auto-
scaling)
The titration is
very slow and
there are too
many points
before the end
point.
50081_Troubleshooting.fm

Troubleshooting

The following table is designed to help identify and solve various problems that may be
encountered while running the AutoCAT.
Probable Cause
No operating power
The screen contrast or
intensity is too low.
Air bubbles have
inadvertently been
trapped while trying to
install the titrant or air is
being sucked into the
system where the tubing
is connected to the
instrument.
Titrant leaks can also
occur when the burette
seals become faulty.
Titrant leaks generally
indicate that a tubing
connector has not been
properly tightened.
Loose tubing connection
Tubing is connected to the
wrong ports on the rotary
valve.
The selected volume
increment is too large.
The volume increment is
too small.
Corrective Action
• Confirm that the power switch on the back of the instrument
has been turned ON.
• Confirm that the power cord is fully inserted into the back of
the instrument and that it is properly plugged into the wall
outlet.
• Confirm that there is power to the wall outlet.
• Verify the integrity of the fuses; change if necessary. See
Section 9.3 Replacing the Fuse on page 140.
• While in the Methods menu, press the 0 to darken, and/or 7
to lighten until the desired screen intensity and contrast
is obtained.
• Verify that the inlet tube for the titrant is secure and below the
surface of the titrant solution inside the titrant bottle.
• Verify that the all the tubing connections are tight. If the
threads of tubing connection are damaged or stripped, and
cannot be properly tightened, they must be replaced.
• Select Titrants>Burette functions>Flush. Lightly tap the
tubing while the instrument is flushing to purge air bubbles
from the system.
• Tighten the leaking tube connection. If the tube connection
has been damaged, replace the tubing.
• Verify the integrity of the burette seals. If the burette seals are
leaking, replace the burette.
• Verify that the inlet tube for the titrant is secure and below the
surface of the titrant solution inside the titrant bottle.
• Verify that the all the tubing connections are tight. If the
threads of tubing connection are damaged or stripped, and
cannot be properly tightened, they must be replaced.
• Verify that the tubing sections are connected to the correct
ports on the rotary valve, respectively. Observe the icons.
See Section 2.2 Instrument Assembly on page 15.
• Decrease the volume increment. The volume increment is
user adjustable during the titration procedure.
• Increase the volume increment. The volume increment is
user adjustable during the titration procedure.
Troubleshooting
Page 141