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2nd Example:
The 20 psi transducer has an offset of .1 volts and will have an output of 5.1 volts
for a 20 PSI pressure. The DATUM 2000™ has a 2.4993 reference voltage.
3rd Example:
A bidirectional transducer has +/- 2.5 volt output for +/- 14.70 reading. The DATUM
2000™ has a reference voltage of 2.5082 volts.
Slope
=
20 - 0
= 4
5.1 - .1
Offset
=
0 - 4 x .1
= -.4
Pressure (@ 0)
=
4x 0 -.4
= -.4
Pressure (@ Ref)
=
4 x 2.4993 -.4
= 9.597
Slope
=
14.70 - (-14.70)
= 5.88
2.5 - (-2.5)
Offset
=
14.70 - 5.88 x 2.5 = 0
Pressure (@ 0)
=
0 x 5.88 - 0
= 0
Pressure (@ Ref)
=
2.5082 x 5.88 - 0 = 14.75
8.4 Calibrating the DATUM 2000™ for a transmitter using the internal
reference voltage
The DATUM 2000™ has a very stable internal reference voltage which can be used
for calibration with transmitters. Before proceeding you must locate the label on the
bottom of the DATUM 2000™ which indicates the reference voltage and the value of
the transmitter input impedance for the channel you wish to calibrate.
