Kistler-Morse KM Microcell Bolt-On - Manual (Page 35)

PROBLEM 3. SUDDEN CHANGE
IN DISPLAY READING OR SYSTEM
REQUIRES FREQUENT
CALIBRATION.
EXPLANATION
A single broken Microcell™ can cause indicated
weight to shift up or down by a large amount,
up to 100% of full-scale live load.
Problem Likely to be Noticed
On system that previously functioned
correctly.
Solution
Check voltage outputs of individual
Microcells™ (see TESTING WITH A
KISTLER-MORSE
® TEST METER in Chapter 2).
Voltage should be between -500mV and
+500 mV on installed Microcells™. If not,
check Microcell™ resistance as described in
Problem 1.
EXPLANATION
Slipping of Microcell™ can cause indicated weight
to shift suddenly.
Problem Likely to be Noticed
Shortly after initial installation.
Solution
If broken Microcell™ is not indicated, perform
the following procedure:
1. Carefully remove environmental cover from
Microcell™.
2. Tighten Microcell™ #8-32 socket head
cap screws, following procedure in
appropriate Microcell™ Installation
Chapter (Chapter 3 for vertical column legs
or Chapter 4 for horizontal beams).
3. Replace environmental cover on
Microcell™. Follow procedure in
appropriate chapter on installation.
CAUTION
Only use Sikaflex 1A polyurethane sealant
or Dow Corning RTV 738 or RTV 739. Other
sealants may contain acetic acid, which is
harmful to sensors and electronics.
EXPLANATION
Sudden change in weight reading can be caused
by problems with signal processor.
Problem Likely to be Noticed
Shortly after initial installation
or on system that
previously functioned correctly.
Solution
Check signal processor excitation voltage and
incoming AC voltage for accuracy and stability
(refer to signal processor manual).
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