Rockwell Automation Publication 1444-UM001D-EN-P - June 2018
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Measurement Definition
Chapter 4
DC
The remaining configurations are applied on the DC page for each channel of
the pair. How each channel is configured depends on which is the sensor for
the short side measurement, and which is the long side measurement.
Channel 0/2 DC Page Configuration
The 1444 monitor requires that the short side sensor is input to the first
channel of the pair.
Figure 73 - Module Properties - Short Side Sensor
Table 37 - Complementary Differential Expansion Configuration - Short Side Sensor
Parameters
Values
Comments
Units
Select from presented
displacement units
Differential Expansion measurements are made using
eddy current probes. Configuration of the units, time
constant, and calibration units are the same as for
Normal Thrust measurements (
Sense control is fixed at “Away” for the short side probe.
Time constant
0.1…60.0 seconds
Calibration units
EU (0)
Volts (1)
Calibration offset
-50000…50000
For the short side probe, the offset is the measured
offset when the shaft is at its cold / zero position.
Always use the actual, initial gap of the probe. The gap
can be measured with a DMM at the ECP system probe
driver. Or the gap can be measured in the tag output
upon start-up of the Dynamix 1444, and can then be
entered into the system and the system reconfigured
later.
Overall axial offset
-50000…50000
No value must be entered into the Overall Axial Offset
entry box unless the starting value for the expansion
measurement is required to start at other than a zero
value due to DCS or other control system requirements.