Allen-Bradley 1444-TSCX02-02RB User Manual page 174

Chapter 4 Measurement Definition
174
Figure 68 - Rotor Hot Position
Definitions
See Figure 67 and
Short Probe
The probe that is mounted at the rotor short end, which is oriented
toward rotor long. Rotor short is the zero or cold position of the turbine
rotor.
This probe must be input to the first channel of the pair that is used for
the measurement (channel 0 or 2).
Long Probe
As the rotor grows in length, it is toward the rotor long position. The
probe that is located where the rotor is growing toward is the long probe,
and is oriented toward rotor short.
This probe must be input to the second channel of the pair that is used
for the measurement (channel 1 or 3).
Gap S
The gap between the short probe and the rotor short side of the target.
During installation, the probe is "gapped" (positioned) such that the gap
is near to the minimum of its usable linear range. This gap assumes that
the rotor is at its cold / zero position.
Rockwell Automation Publication 1444-UM001D-EN-P - June 2018
Figure 68.