DAD 141.1 Technical Manual, Rev. 2.5 – April 2015
Page 26 of 54
8.2. Example 2
– Calibration procedure using load cell’s
mV/V sensitivity
3 Leg tank or silo fitted with 3 load cells of 1000kg;
load cell signal @ 1000kg = 2 mV/V.
Dead load of tank / silo is 600kg.
Live range is 1500 kg, step size is 0.5kg.
It is assumed that the load cell system is connected
to the DAD 141.1 and the power is on. The maximum
and minimum display values, display increment size
and decimal point position should be defined prior to
carrying out the calibration (See chapter 7.5 menu 3).
For this example the display maximum is defined as
1600.0kg, the display minimum is -200.0kg, the
Display step size is 0.5kg.
Remember that all parameters of the menues 1.1 - 1.3, 2.1 - 2.3 and 3.1 - 3.3 can only be accessed or
changed after remove the jumper on the seal switch pins (28).
a
A scale calibration by using weight(s) can
only
be performed in the scale status ‘
no motion
‘. This requires
in any case to check the settings of menu 4.
Recommendations for setup as follows:
-
Menu 4.1: set cut off frequency to 4.1.7 = 0.5Hz
-
Menu 4.2: choose IIR filter
-
Menu 4.4.1: set no motion range e.g. to 2, which means for this example 0.2kg
-
Menu 4.4.2: set no motion time to 1000, which means 1000ms or 1s
In case of outdoor application or indoor with a lot of mechanical noise from the floor/ground, may be you
have to change the ‘no motion‘ settings.
b
Go to Menu 3.2 (display step size) by using the
UP/DOWN
and
ZERO
keys. The display shows the
actual step size, e.g. 1. Now you can change step size by using the
UP/DOWN
keys and set to 5.
Press the
ZERO
key to store & leave menu point. This procedure defines the step size to 5, which leads
with the setup of decimal point to 0.5kg steps.
c
Go to Menu 3.3 (decimal point position) by using the
UP/DOWN
and
ZERO
keys. The display shows the
actual decimal point, e.g. 0.0. Now you could change decimal point position by using the
UP/DOWN
keys, but in this example we keep the setup. Press the
ZERO
key to store & leave menu point.
This procedure defines the decimal point position to 0.0, which leads to weight readings of e.g. 498.5kg.
d
Go to Menu 1.3 (cal. zero in mV/V) by using the
UP/DOWN
and
ZERO
keys. The display shows the
actual mV/V value, e.g. 0.4107. Make sure that the tank/silo is empty or at the point where you want
the display to read zero. Press the
ZERO
key to set the display reading to 0000.0kg.
This procedure defines the actual zero calibration point. Leave this menu point with
ZERO
key.
In case you want to setup absolute zero to 00.0000mV/V, you can do this via
ZERO
key and using
UP/DOWN
and
TARE
keys etc.
e
Go to Menu 2.1 by using the
UP/DOWN
and
ZERO
keys. Set the display to read the span value @
summary of load cell capacity. For this example, we use 3 load cells with 1000kg capacity each, set the
display to read 3000.0. By using the
UP/DOWN
and
TARE
keys you have to setup each number of the 6
digit display to 03000.0. Press now
ZERO
key for storage. This procedure defines the span calibration
value. Leave this menu point with
ZERO
key.