Kistler-Morse KM L-Cell Bolt-On - Manual (Page 81)

Appendix E. Troubleshooting
E-4
Problem Problem Details Solution
Small Amplitude
Changes or Erratic
Fluctuations in
display readings Fluctuations can be
caused by problems with
signal processor. Check signal processor excitation
voltage and incoming AC voltage for
accuracy and stability (refer to signal
processor manual).
Repeatable Drift
over 24-hour
Period Periodic drift is most likely
caused by vessel thermal
expansion due to sun’s
radiation or vessel’s
response to its own
heating cycles. 1. If periodic drift is outside specifica-
tions (Appendix A & B), contact KM.
2. If keeping long-term records of
material levels, take readings at same
time each day to minimize error.
Sudden Change in
Display Reading or
System Requires
Frequent
Recalibration A single broken L-Cell
can cause indicated
weight to shift up or down
by large amount, up to
100% of full-scale live
load. Check voltage outputs of individual
L-Cells (refer to Chapter 2, Pre-Installa-
tion procedures). Voltage should be
between -200 mV and +200 mV on
installed L-Cells. If not, check L-Cell
resistance as described in Troubleshoot-
ing Section page E-2.
Sudden change in weight
reading can be caused by
problems with signal proces-
sor. Check signal processor excitation
voltage and incoming AC voltage for
accuracy and stability (refer to signal
processor manual).
Slipping of L-Cell can
cause indicated weight
to shift suddenly.
If a broken L-Cell is not indicated,
perform following procedure:
1. Carefully remove environmental
cover from L-Cell.
2. Retighten L-Cell #6-32 socket
head cap screws, following
procedure in L-Cell Installation
Chapter applicable to installation.
3. Replace environmental cover on
L-Cell. Follow procedure provided
in L-Cell Installation Chapter
applicable to installation.
CAUTION
Only use Sikaflex 1A
polyurethane sealant or
Dow Corning RTV 739
or RTV 738. Other sealants
may contain acetic acid, which
is harmful