Hardy HI 1756-nDF - Manual (Page 57)

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Chapter 6
F - Verify Individual Load Cell Millivolt Readings
Testing an individual load cell signal output requires an IT Summing Junction box or
millivolt meter.
Use the load cell certificate to verify the millivolt per volt (mV/V) rating:
Example: 3mV/V load cells produce approximately 15mV at full load. That is 5 volts
excitation x 3 mV/V. At a scale capacity of 1,000 lbs. with 100 lbs. of deadload when
empty, the load point mV reading should measure 1.5mV.
F
Select
IT
TEST MV/V
IT TEST Checks
individual load
sensor output
mV/V readings
Select
load
sensor
Record load
sensor mV/V output
level for
comparison
Repeat for all load
sensors
MV/V
readings
acceptable?
Zero mV/V
reading
1) No dead load
Apply load and re-test.
2) Wiring error
Verify color code using the
load cell certificate
3) Open bridge circuit
Disconnect power and verify
load point bridge resistance
reading with an Ohmmeter
1) Stressed load cell, remove
all load and re-test.
2) Excessive loading
For additional
testing go to:
H
High mV/V
reading
K
Defective load Cell
Replace and repeat
TEST F
TEST COMPLETE
Yes
No
High mV/V
reading