Emerson Vission 20/20, Operation And Service Manual

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13 – 5
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 2.0
Section 13 • Instruments Calibration
Figure 13-5. Instruments Calibration Screen - Analog Inputs (Page 5)
Offset:
• Once the two-point calibration is completed, it is not
uncommon for there to be a small error. By entering
the value of the error from the calibrated value and
the actual value into the adjustment entry box, that
error will be added/subtracted from the total offset.
The offset is applied to the calibrated value which
should correct the error.
Range:
• Here the operator de
fi nes the signal type and range
transmitted by the instrument. The operator can
choose from several prede
fi ned ranges in the drop-
down box or enter a value.
Analog Outputs
The Analog output card of the Vission 20/20 generates
a 4–20mA signal to any attached devices. However, it is
not uncommon that small difference in the board com-
ponents might result in small difference in the output.
So this screen offers the operator the ability to
fi ne tune
the upper and lower output values, see Figure 13-6.
Test Limits:
• By pressing either the Test Min or Test Max buttons,
the output will go to either 4ma or 20 ma. The opera-
tor can then measure the output for accuracy.
Min (mA):
• If the 4ma output has an unacceptable amount of
error. The operator can use the “+” & “-” buttons to
adjust the output.