PT610, PT620, PT630
Instruction Manual
79
value shown on the display, enter the new value via the keys. This load value should be between 35%
and 65% of the scale’s capacity.
5. Place the test weights or another convenient weight of known value on the scale.
6. Press the
<ENTER>
key to start the first step of span calibration. The
[WAIT]
message will be
shown on the display for approximately 10 seconds while the first step span calibration is being
performed.
7. At the
[LOAD 2]
prompt, the test weight value that will be used for the second step of calibration is
seen on the display as
[XXXXXX]
. If the value of the test weights that will be used is different from the
value shown on the display, enter the new value via the keys. This weight should equal at least 90% of
scale capacity, preferable at scale capacity as much as is practical.
8. Place the test weights or another convenient weight of known value on the scale.
9. Press the
<ENTER>
key to start the second step of span calibration. The
[WAIT]
message will be
shown on the display for approximately 10 seconds while the span calibration is being performed.
Note:
The accuracy of the calibration cannot be any greater than the accuracy of the calibration weight.
6.6.1.3 [613 ELECTRONIC] – vCal
vCal has some limitations but is a very good way to get a weighing system up and running that can later
be fine tuned with zero and span adjustments (below) or by adjusting the vCal input parameters.
Warning:
The scale capacity and division
[523]
(6.5.2.3) must be entered before performing vCal.
Warning:
vCal is theoretical calibration by calculation without taking into account external influences.
Corner adjustments, as in a summing box, will make the calibration incorrect. Lengthening or
shortening load cell 4 wire cable connections, variations in gravitational acceleration (g), mechanical
influences and structure geometry variances can all reduce the accuracy of vCal.
This parameter lets you to perform calibration without using any test weights. The A/D coefficients are
adjusted in production for ito maximise vCal accuracy. The calibration coefficients are calculated from
scale capacity, total load cell capacity, load cell full scale output and estimated dead load. If the
conditions are convenient for zero calibration, you may perform automatic zero adjustment with and
empty scale (more accurate) instead of entering estimated dead load.
1. Press the
<ENTER>
key at the
[613 ELECTRONIC]
prompt to start the calibration.
2. At the
[TOTAL LC CAPACIT]
[XXXXXX]
prompt, enter the total load cell capacity via the keys and
press the
<ENTER>
key to go to the next step.
Example : If the weighing system has 4 pcs. 1000 kg load cell, enter 4000.
3. At the
[AVARAGE LC OUT]
[XXXXXX]
prompt, enter the load cell output in mV/V via the keys. If
the weighing system has more than one load cell, calculate the mean (average) value of all the load
cell mV/V outputs indicated on the certificates of the load cells. Press the
<ENTER>
key to go to the
next step.
Example: If load cell outputs are LC1=2.0010, LC2=1.9998, LC3=1.9986 and LC4=2.0002, the mean
value will be;
Mean of LC outputs = (2.0010 + 1.9998 + 1.9986 + 2.0002) ÷ 4 = 1.9999 mV/V.
4. At the
[ZERO ADJUST]
prompt, you can perform an automatic zero adjustment instead of entering
an estimated dead load (as below). To skip this step and enter an estimated dead load (5.) press the
<UP>
key followed by the
<ENTER>
key.
4a. To perform an automatic zero calibration press the
<ENTER>
key at the
[ZERO ADJUST]
prompt.
4b. The prompt
[UNLOAD THE PAN]
appears. Remove any weight on the platform or scale, then
press the
<ENTER>
key.
3c. The display will show the
[WAIT]
message during zero adjustment. During this time the scale must
be unloaded and stable. Vcal will be completed after approximately 10 seconds.
5. At the
[ESTIM DEAD LOAD]
[XXXXXX]
prompt, enter the dead load value of the weighing system
(in the current units) by using the keys. Press the
<ENTER>
key to go to the next step.
Note:
A previous vCal will be overwritten by a calibration with weights
[611], [612]
or span adjustment
[622]
.
Note:
Gravity adjustment
[624], [625]
or span adjustment under load
[623]
cannot be performed after
vCal.
Note:
For dead load correction you can change the dead load value after testing the scale and then
adding the displayed gross weight value of the unloaded scale to the dead load value entered above.
Do not press the
<ZERO>
key after switching the instrument on after calibration, and the power on zero
and automatic zero tracking have been disabled to determine the dead load error.
Note:
Dead load value is cancelled after automatic zero adjustment.
6.6.2 [62_] – Adjustment
These parameters require the settings DIP switch to be ON. The zero and span can independently be