Rice Lake 720i Programmable Indicator/Controller - Installation Manual - Manual (Page 53)

Calibration 47
4.0 Calibration
The 720i can be calibrated using the front panel, serial commands, or Revolution III
®
. Each method consists of the
following steps:
• Zero calibration
• Entering the test weight value
• Span calibration
• Optional five-point linearization
• Optional rezero calibration for test weights using hooks or chains
The following sections describe the calibration procedure for each of the calibration methods.
SCALES SERIAL FEATURE PFORMT DIG I/O ALGOUT VERS
WZERO WVAL WSPAN WLIN REZERO
POINT 4 POINT 5 POINT 1 POINT 2 POINT 3
GRADS CALIBR
SCALE 1
Figure 4-1. Calibration (CALIBR) Submenu
4.1 Gravity Compensation
Gravity compensation for latitude and elevation is available for the 720i . To calibrate with gravity compensation,
the LOCALE parameter under the FEATURE menu must be set ON, and the LATUDE (latitude) and ELEVAT
(elevation, in meters) parameters set before calibrating the indicator (see Figure 3-10 on page 32).
If the indicator is later installed at a different location, gravity compensation can be applied to a pre-calibrated
indicator by adjusting the LATUDE and ELEVAT parameters.
4.2 Front Panel Calibration
The CALIBR submenu (under the SCALES menu, see
Figure 4-2) is used to calibrate the
720i .
WZERO
+ / -
1440
Last Zero Calibrate MV
Figure 4-2. WZERO Calibration Display
The zero, span, and linear calibration point displays
provide a set of softkeys used specifically for
calibration procedures:
+/– Toggles to allow entry of negative or
positive values
Last Zero Recalls the last established zero value to
allow calibration without removing tests
weights or product from scale.
Calibrate Performs calibration for the selected
point
Millivolts (or Counts )
Toggles between display of captured A/
D counts and captured millivolts values;
allows entry of calibration values in mV
or counts
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
Down key, then select the scale to be calibrated.
P r e s s D o w n a g a i n ( G R A D S p a r a m e t e r
highlighted), then press Left to highlight the
CALIBR submenu (see Figure 4-1). Press Down to
go to zero calibration (WZERO). See Figure 4-2 on
page 47
.