7 calibration with mv/v value [by mv/v, 1 span, 2 dead load – Rice Lake PR5230 Fieldbus Transmitter User Manual
Page 118: Calibration with mv/v value [by mv/v, Commissioning, Pr 5230 instrument manual
Commissioning
PR 5230 Instrument Manual
EN-118
Sartorius
5.4.7
Calibration with mV/V Value [by mV/V]
The scale can be calibrated without weights. During input of the load cell mV/V value, the acceleration of
gravity at the place of installation can be taken into account. The STAR load cell data is based on the
acceleration of gravity effective at Hamburg, Germany: 9.81379 m/s².
SPAN
Span indicates the equivalent input voltage in mV/V related to the maximum capacity (Max) of the scale. It is
calculated as follows:
cells)
load
of
number
*
load
(nominal
capacity
cell
load
]
[mV/V
Cn
y
sensitivit
cell
load
capacity
maximum
=
[mV/V]
SPAN
*
Load cell sensitivity C
n
= rated output C
n
(see technical data of the load cell)
5.4.7.2
Dead Load
The input voltage in mV/V equivalent to the dead load can be calculated by using the dead load rather than
the maximum capacity in the formula specified above.
Normally, calculation of the dead load (scale without load/empty hopper) is not necessary.
Subsequent dead load correction (as described in Chapter 5.4.9) can be used for later re-determination of the
dead load, when the scale/hopper is empty.
Example
-
Load cell(s) with rated output C
n
of 2 mV/V
-
at nominal load of 2,000 kg
-
dead load 500 kg
-
load cell supply voltage 12 V DC
The calibration dialog provides an overview of all settings:
Weighingpoint/WP A/
Calibration
Max
1000 d
1000 kg
Scale interval
1000 d
1 kg
Deadload at
500.00 kg
0.500000
Max at
1000.00 kg
1.000000
Calibrated at
1000.00 kg
1.000000
Sensitivity
2500.00
12.000000
After selecting [mV/V], the values for the Max and for the dead load (if necessary) can be entered.
The next step is calculation of the test value with [CalcTest] (see Chapter 5.4.10).
The calibration is completed by pressing
(see Chapter 5.4.12).