SERIES 8162 STRAIN GAGE SIGNAL CONDITIONER MANUAL
3
Either 5-volt or 10-volt bridge excitation can be
selected. In general, 5-volt excitation is used with
120
Ω
transducers, and the 10-volt excitation is used
with 350
Ω
and 700
Ω
transducers.
Excitation voltage is set by the position of the P1
Jumper. See Figure 4. Jumping pins 1 and 2 will set
the conditioner to 10 V
EXC
. Jumping pins 2 and 3
will set the conditioner to 5 V
EXC
.
6.0
Calibration
The Series 8162 can be calibrated using (2) different
methods. The first method uses actual or simulated
Zero and Full Scale (FS) inputs. Actual inputs may
come from a strain gage transducer loaded with
calibrated weights. Simulated inputs may come from
a strain gage bridge simulator.
The second method utilizes an R
CAL
resistor to
simulate a load on a strain gage bridge. The R
CAL
resistor, located in the R12 position in Figure 4, is
shunted across one arm of the strain gage bridge
when the R
CAL
Switch (SW1) is depressed. The
shunt produces an imbalance equivalent to that of a
particular value of mechanical input. If this
Equivalent Input value is accurately known, it can be
used as a reference point for shunt calibration of the
system. Upon completion of installation of the
transducer and its associated cabling, the user can:
a.
Perform an overall deadweight calibration using
a precisely known value of mechanical input.
The calibration can then be transferred to the
installed calibration resistor for convenience in
checking later.
b.
Replace the installed calibration resistor with
one supplied by the transducer manufacturer, or
an equivalent resistance value, to achieve a
precisely known equivalent input, allowing the
instrument sensitivity to be adjusted correctly.
c.
A 30K ohm resistor is installed at the factory and
is used during final checkout of the instrument.
It is replaced with a more proper value resistor
when calibrated with a specific transducer to
produce a more accurate shunt value. The
resistor is mounted internally on terminal R12
located on the printed circuit board in the
instrument. See Figure 4. It can be reached by
removing the cover.
Note: Soldering is not required to remove or install
the shunt calibration resistor. When an amplifier is
purchased with a specific sensor as a system, PCB
will install the proper value shunt resistor in the
amplifier.
R
CAL
Polarity (+R
CAL
/ -R
CAL
)
The default R
CAL
polarity setting of the Series 8162
Signal Conditioner is positive (+). Depending on the
particular
sensor
being
calibrated
with
the
conditioner, +R
CAL
and/or -R
CAL
data is provided on
the calibration certificate.
The polarity of the R
CAL
may be switched by
changing the solder jumper position on the R
CAL
solder tabs located on the internal circuit board of the
conditioner. See Figure 4 for the R
CAL
solder tab
locations. Solder applied to jumper 1 will yield a
+R
CAL
, solder applied to jumper 2 will yield a -R
CAL
.
