OHAUS TROOPER, Руководство по обслуживанию

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2-5
CHAPTER 2 DIAGNOSIS
SYMPTOM
Scale can be turned on but will
not calibrate (Cont.).
PROBABLE CAUSE
Load Cell assembly defec-
tive.
Main PC Board defective.
REMEDY
With the platform in place and the scale
turned on, measure across pins -SIG
and +SIG on the PC Board. Typical no
load output from the Load Cell is -1.0
mv to + 1.0 mv. If the output exceeds
this value, replace the load cell.
If this measurement is within limits,
place a full load on the platform and
measure again. The difference between
zero and full load readings should be
as shown in the table below. If the
reading is out of this range, try replac-
ing the Load Cell. -> Repair Procedures
3.3.
NOTE : Readings may differ from
table due to load cell tolerances.
Reassemble, the scale, perform tests in
Section 5 and verify operation.
If the above readings are within limits,
the Main PC Board is defective.
To check the Main PC Board if unsure
about the load cell, connect a known
good load cell or load cell simulator to
connector J4 as shown in Figure
2-1. Use an output of 0 mv/V for CAL
ZERO and 1 mv/V for span calibration.
If unable to calibrate, the Main PC
Board is defective. Replace Main PC
Board. -> Repair Procedures 3.2.
TABLE 2-5 TROOPER SCALE - CANNOT CALIBRATE (Cont.).
LOAD CELL OUTPUT READINGS
MODEL SPAN SIGNAL
TR3RS 4.0-5.0mv
TR6RS 3.5-4.5mv
TR15RS 4.5-5.5mv
TR30RS 6.5-8.3mv
NOTE : Span signal readings are approximate.
If readings are slightly above or below
these limits, the loadcell may still function properly.