Measurement Technology NW
LCI-90 Operator Manual
Page 33
5.6
Shunt Calibration
To perform a shunt calibration, press
CALB
to display the main
2.0 CALIBRATION
menu shown below. Select Item 3 and press
ENT
to activate the edit keys. Press either
INCR
or
DECR
to toggle between
ON
and
OFF
. Press
ENT
to accept the selection. At
this time the contacts on the Opto 4 module will either be closed
(ON)
or opened
(OFF)
.
2.0 CALIBRATION
1
TENSION (THREE METHODS)
2
TENSION TARE
OFF
>
3
SHUNT CAL
ON
4
WRAP ANGLE
120 DEG
5
PAYOUT SCALE
2.800 P/FT
6
PAYOUT PRESET
150 FT
5.6.1 Shunt Calibration
The Shunt Cal function requires a load pin or cell with an internal relay that, when
energized, connects a precision resistor in parallel with one leg of the bridge. This
perturbation simulates a known change in tension, which can be used to verify the
calibration of the unit. Setting Shunt Cal to ON closes the contacts of the DC output
module installed in the Opto 4 slot. A 24VDC relay in the load pin is appropriate.