GSE Porta-Tronic, Руководство по установке

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Porta-tronic Installation Guide
2
4. After each corner has been checked and calibrated, make a final check of your calibration.
3. Legal for Trade
When the Porta-Tronic is used in a legal-for-trade application, sealing of the scale platform is done using
one of two methods.
♦
If a lead wire seal is required, loop the wire through the two holes provided on either end of the
summing box. Add the seal wire after calibration and corner adjustments.
♦
If a foil seal is acceptable, apply the foil seal to the outside of the summing box or to the access plate
enclosing the summing box.
4. Troubleshooting
4
4
.
.
1
1
L
L
o
o
a
a
d
d
C
C
e
e
l
l
l
l
T
T
e
e
s
s
t
t
i
i
n
n
g
g
Before testing, it is suggested that each load cell be carefully inspected for physical damage.
4
4
.
.
2
2
T
T
e
e
s
s
t
t
i
i
n
n
g
g
Z
Z
e
e
r
r
o
o
B
B
a
a
l
l
a
a
n
n
c
c
e
e
Changes in zero balance usually occur if the load cell has been overloaded. Some change may
be tolerated depending on the application.
Use a voltmeter set to millivolts. Measure the load cell output under no load conditions. It should
be less than 10% of the full scale output.
4
4
.
.
3
3
T
T
e
e
s
s
t
t
i
i
n
n
g
g
B
B
r
r
i
i
d
d
g
g
e
e
R
R
e
e
s
s
i
i
s
s
t
t
a
a
n
n
c
c
e
e
Changes in bridge resistance are most often caused by a failure of a compensating element, a
broken bridge or burned bridge. Usually failure is the result of an electrical transient such as
lightning.
With an ohmmeter, measure the resistance across each pair of input and output leads. The
output resistance of the bridge is normally about 350 ohms for single ended beams and canisters
and 700 ohms for double-ended load cells. Refer to the calibration certificate shipped with the cell
for the actual values. Readings beyond these limits suggest damage and the load cell should be
thoroughly inspected.
4
4
.
.
4
4
T
T
e
e
s
s
t
t
i
i
n
n
g
g
R
R
e
e
s
s
i
i
s
s
t
t
a
a
n
n
c
c
e
e
t
t
o
o
G
G
r
r
o
o
u
u
n
n
d
d
Electrical leakage is usually caused by water contamination within the load cells or cables.
Whether the leakage can be tolerated depends on the application and electronic instrumentation
being used. An unstable output is most often caused by contamination.
With a megohmmeter, measure the resistance between all 7 leads tied together (6 live leads and
1 shield) and the load cell body. The reading should be 5000 megohms or more. If the load cell
fails this test, remove the ground wire and test with only the 6 live leads. If it tests good, an
insulation problem is suspected.