Rice Lake 820i Programmable Indicator/Controller - Installation Manual - Manual (Page 53)

Calibration 49
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
hooks or chains on the scale for zero
calibration.
2. With the
SCALES
menu highlighted, press the
d o w n
key, then select the scale to be
calibrated. Press
d o w n
again (
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 48.
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, press
down
to show the
stored calibration weight value. Use the
numeric keypad to enter the actual value of
the calibration test weights, then press
enter
to
save the value and go to span calibration
(
WSPAN
).
5. Place test weights on scale. 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 five
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
first 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 five 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 79 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
4. Send the SC.WSPAN#n serial command to
calibrate span.