Kistler-Morse Weigh II, Installation And Operation Manual

Page: 47 / 120

Chapter 6. Calibration
6-9
12. Use the keypad or the Up and Down
Arrow Keys to input a value for zero counts
(the number of counts associated with
zero live load). Press the Enter Key to
save the value in memory. The display
flashes a message acknowledging your
entry and returns to:
13. Press the Esc Key to scroll up the
menu tree or press the Auto/Man Key to
return the display to vessel monitoring.
Displaying the Manual
Calibration Parameters
The second page of the Manual Cal Menu has
a display function. Accessing this menu
allows you to view the following calibration
values that have been entered or internally
calculated for the selected vessel:
• Cnts/mV (digital counts per millivolt
of signal)
• 0mV cnts (number of digital counts
corresponding to 0 millivolts of signal)
• H_SPAN_W (hi span weight) — blanked
out with “---” after a manual calibration
• L_SPAN_W (lo span weight) — blanked
out with “---” after a manual calibration
• H_SPAN_C (hi span counts) — blanked
out with “---” after a manual calibration
• L_SPAN_C (lo span counts) — blanked
out with “---” after a manual calibration
• ZERO_WGT (zero calibration weight,
which is zero for manual calibrations)
• ZERO_CNT (entered counts corresponding
to zero live load)
• SCF_WGT (entered scale factor weight)
• SCF_CNT (entered scale factor counts)
Follow this procedure to display the auto
calibration parameters.
1. While in the Manual Cal Menu, access the
second page by pressing the Menu Key
until the display shows:
2. Press the F3 Key to access Disply . The
display looks like this:
3. Press any key other than the Esc or Auto/
Man Key to cycle through the parameters.
4. Press the Esc Key to scroll up the menu
tree or press the Auto/Man Key to return
the display to vessel monitoring.
Resetting the Manual
Calibration Parameters
The third page of the Manual Cal Menu has a
reset function. Accessing this menu allows
you to reset the calibration values to the
factory-set default values, which are
listed below:
• Cnts/mV — dependent on Gain value (see
Chapter 7, Service). Value is 699.05 for the
default
Gain of 2.
• 0mV cnts — 1,048,576
• H_SPAN_W ---
• L_SPAN_W ---
• H_SPAN_C ---
• L_SPAN_C ---
• ZERO_WGT — 0
• ZERO_CNT — 1,048,576
• SCF_WGT — 9,999
• SCF_CNT — 250,000
Linear
The linearization function can be used to
correct nonlinearities from a vessel’s sensor/
transducer output. Use of this function may
be required if you notice one of the following
after you have correctly calibrated the system
(using either Automatic or Manual Calibra-
tion):
• The Weigh II gives accurate results when
the live load is close to 0 and close to
the full scale (maximum live load) value,
but is
consistently inaccurate between
those values.
• The Weigh II gives accurate results over
some or most of the live load range, but is
consistently inaccurate in one area.
The word “consistent” refers not only to an
error occurring, but that the error is approxi-
mately the same each time. This type of error
may be caused by a non-linear response of
the vessel’s structure to changes in load.
This type of error can also result from layering
of multiple types of material in the vessel,
with differing densities, in distinct, consis-
tently defined layers.
MANUAL CAL MENU
Zero_Cnt Disply
F1 F2 F3
MANUAL CAL MENU
Zero_Cal Disply
F1 F2 F3
Cnts/mV: X
0mV cnts Y
F1 F2 F3