Rice Lake 920i Installation Manual V2.0 - Manual (Page 51)

Calibration 47
To calibrate the indicator using the front panel, do the
following:
1. Place the indicator in setup mode (display
reads Scale Configuration ) and remove all
weight from the scale platform. If your test
weights require hooks or chains, place the
h o o k s o r c h a i n s o n t h e s c a l e f o r z e r o
calibration.
2. With the SCALES menu highlighted, press the
d o w n key, t h e n s e l e c t t h e s c a l e t o b e
c a l i b r a t e d . P r e s s d o w n a g a i n ( G R A D S
parameter highlighted), then press left to
h i g h l i g h t t h e C A L I B R s u b m e n u ( s e e
Figure 4-1). Press d o w n to go to zero
calibration ( WZERO ). See Figure 4-2 on page
46.
3. Ensure scale is empty, then press down again
to show the current WZERO value, then press
the
Calibrate softkey to calibrate zero. When
complete, the new A/D count for the zero
calibration is displayed. Press
enter to save
the zero calibration value and go to the next
prompt (
WVAL ).
4. With WVAL displayed, place test weights on
the scale and press down to show the test
weight value. Use the numeric keypad to enter
the actual test weight, then press
enter to save
the value and go to span calibration ( WSPAN ).
5. Press down again to show the current
WSPAN value, then press the Calibrate
softkey to calibrate span. When complete, the
new A/D count for the span calibration is
displayed. Press
enter again to save the span
calibration value and go to the next prompt
(
WLIN ).
6. Five-point linearization (using the WLIN
parameter) provides increased scale accuracy
by calibrating the indicator at up to Þve
additional points between the zero and span
calibrations.
Linearization is optional: if you choose not to
perform linearization, skip the WLIN
parameter; if linearization values have
previously been entered, these values are reset
to zero during calibration. To perform
linearization, follow the procedure below:
With
WLIN displayed, Press down to go to the
Þrst linearization point ( POINT 1 ). Press
down again to show the weight value prompt
( WGT 1 ), then down once more to show the
weight value. Place test weights on the scale,
then use the numeric keypad to enter the
actual test weight value. Press
enter to save
the value and move to the calibration ( CAL 1 )
prompt. Press down to show the current
calibration value, then press the Calibrate
softkey to calibrate the linearization point.
When complete, the A/D count for the linear
calibration is displayed. Press
enter again to
save the calibration value and go to the next
prompt (
POINT 2 ).
Repeat for up to Þve linearization points. To
exit the linearization parameters, press the
up
key to return to WLIN.
7. The optional rezero function is used to
remove a calibration offset when hooks or
chains are used to hang the test weights.
NOTE: The rezero function cannot be used
with five-point linear calibration.
¥ If no other apparatus was used to hang the
test weights during calibration, remove
the test weights and press
up to return to
the CALIBR submenu.
¥ If hooks or chains were used during
calibration, remove these and the test
weights from the scale. With all weight
removed, go to the REZERO parameter,
then press
down to show the current zero
value. Press the Calibrate softkey to
adjust the zero and span calibration
values. Press
enter or up to return to the
CALIBR submenu.
8. Press up to return to the SCALES menu, or
press the Save and Exit softkey to exit setup
mode.
4.3 Serial Command Calibration
To calibrate the indicator using serial commands, the
indicator serial port must be connected to a terminal
or personal computer. See Section 2.3.3 on page 7 for
serial port pin assignments; see Section 9.0 on
page 78 for more information about using serial
commands.
Once the indicator is connected to the sending device,
do the following:
1. Place the indicator in setup mode (display
reads CONFIG ) and remove all weight from
the scale platform. If your test weights require
hooks or chains, place the hooks or chains on
the scale for zero calibration.
2. Send the SC.WZERO#n serial command
(where n is the number of the scale) to
calibrate zero.
3. Place test weights on the scale and use the
SC.WVAL command to enter the test weight
value in the following format:
SC.WVAL#n=vvvvv<CR>
4. Send the SC.WSPAN#n serial command to
calibrate span.
5. Up to Þve linearization points can be calibrated
between the zero and span calibration values.