3. CALIBRATION
(cont.)
This section contains the instructions for calibrating the 5M78. Included is a
functional description of the instrument front-panel (see Figure 2). To perform
calibration, proceed as follows.
Turn power ON to the 5M78 DC Power input terminal (11 to 28 Vdc input)
The front-panel indicator should light green to indicate the application of
dc power. Allow 10 minutes of warmup for stabilization of transducer
characteristics. Open the protective, clear plastic, front cover of the unit.
Set the Coarse Zero and Span controls to the marked label position (
<
, Min
>
).
Position the front panel switches to the desired settings for the application.
Refer to Figure 2 for details. If using Shunt method, refer to step (k).
(b)
(a)
(c)
the Coarse and Fine SPAN controls. If not, adjust the Symmetry control
to obtain the negative Equivalent Input value.
If dead weight calibration is not practical and the transducer calibration
data is unknown, the Equivalent Input value for the factory-installed
calibration resistor can be approximated
mv/v sensitivity rating of the transducer
known.
as follows, assuming that
and the bridge resistance
the
are
13
(m)
With the transducer unloaded, adjust the Coarse Zero control and the Fine Zero
control until the desired analog output is achieved. If greater zero authority is
desired, place the front panel Switch 7 - "Zero Adj" to the extended range. This will allow
the user to obtain 100% zero offset control. The Normal postion of switch 7 allows
for approximately 25% Zero authority.
(d)
the Coarse and Fine SPAN controls. If not, adjust the Symmetry control
to obtain the negative Equivalent Input value.
If dead weight calibration is not practical and the transducer calibration
data is unknown, the Equivalent Input value for the factory-installed
calibration resistor can be approximated
mv/v sensitivity rating of the transducer
known.
as follows, assuming that
and the bridge resistance
the
are
13
(m)
Load the transducer in the positive direction with a convenient dead weight value
(greater than one half of full scale). Adjust Coarse Span for a nominal corresponding output.
Adjust the PHASE control, until a maximum output value is obtained. (Once set for your
transducer, this PHASE ADJUSTMENT step need not be repeated unless a change in
cable length – or transducer – is required). Unload the sensor and re-Zero as needed.
(e)
(f) If the calibration will utilized a known "dead-weight", re-load the sensor and adjust the
Coarse and Fine Span controls for the expected analog output value. Unload - Zero and
Load - Span operations may need to be repeated for analog output precision.
Note: With sensor unloaded, activate & record "SHP" value for furture calibration verification.
If the calibration will utilize the "Shunt" calibration method, refer to step (k).
recommended calibration resistor.
the Coarse and Fine SPAN controls. If not, adjust the Symmetry control
to obtain the negative Equivalent Input value.
If dead weight calibration is not practical and the transducer calibration
data is unknown, the Equivalent Input value for the factory-installed
calibration resistor can be approximated
mv/v sensitivity rating of the transducer
known.
as follows, assuming that
and the bridge resistance
the
are
13
(g)
(m)
Calibration 5M78.3
the Coarse and Fine SPAN controls. If not, adjust the Symmetry control
to obtain the negative Equivalent Input value.
If dead weight calibration is not practical and the transducer calibration
data is unknown, the Equivalent Input value for the factory-installed
calibration resistor can be approximated
mv/v sensitivity rating of the transducer
known.
as follows, assuming that
and the bridge resistance
the
are
13
(m)
the Coarse and Fine SPAN controls. If not, adjust the Symmetry control
to obtain the negative Equivalent Input value.
If dead weight calibration is not practical and the transducer calibration
data is unknown, the Equivalent Input value for the factory-installed
calibration resistor can be approximated
mv/v sensitivity rating of the transducer
known.
as follows, assuming that
and the bridge resistance
the
are
13
(m)
If the transducer is to be also used in the negative realm, load the
transducer in the negative direction with the same dead weight value as
used in step (f) and confirm that the dead weight reading obtained is the
same, but negative polarity, as that of step (f). If not, see steps (i) thru (j).
A Symmetry adjustment is provided to compensate for transducers
that do not have symmetrical sensitivity characteristics. This
adjustment is factory set assuming symmetrical characteristics. If step
(h) indicates that a field adjustment is necessary, proceed as follows.
recommended calibration resistor.
the Coarse and Fine SPAN controls. If not, adjust the Symmetry control
to obtain the negative Equivalent Input value.
If dead weight calibration is not practical and the transducer calibration
data is unknown, the Equivalent Input value for the factory-installed
calibration resistor can be approximated
mv/v sensitivity rating of the transducer
known.
as follows, assuming that
and the bridge resistance
the
are
13
(h)
(i)
(m)
