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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

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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).