F - verify individual load cell millivolt readings, Chapter 6 – Hardy HI 1756-FC User Manual

Page 43

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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

Press ENTER
to check 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

38

Chapter 6

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