Emerson Machinery Health PR 642 Series, Installation Manual

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Sensor fastening
• Use the enclosed nuts when installing sensors with mounting threads
• When installing sensors with mounting threads captive nuts must be used to avoid
loosen of the sensor. Loose parts can fall into the machine and cause damages. A
medium grade removable thread locked (for example Loctite
®
242, blue) is
recommended to secure the sensor.
Measuring track on the measuring target
The measuring track on the measuring target must be free from irregularities as scratches,
corrosion, stress concentrations, metallurgical segregation, high concentricity, etc. These
irregularities may cause changes in the sensor output voltage which are not related to a
real position or vibration signal. The signal caused by these irregularities is called runout.
For the measuring track a surface finish of 0.41 µm to 0.76 µm is recommended.
Free space
Ensure there is 45° of free space around the sensor head for all sensor types except PR
6426, as shown in the left diagram of
Figure 4-2 . The right drawing in Figure 4-2 shows the
required free space around the PR 6426.
Figure 4-2: Free space around sensor head
Free space PR 6422, PR 6423, PR 6424 and PR 6425: ± 45°
Free space PR 6426: minimum = 80 mm; for nominal range ±4 mm and for extended
ranges
CAUTION
If you do not ensure the free space specifications, the measuring range at the upper end
reduces and the linearity error increases.
Maximum axial tilting angle
Ensure that the maximum axial tilting angle alpha is < 2° if using PR 6422, PR 6423, PR
6424 or PR 6425 as shown in
Figure 4-3 , or alpha < 1.6° if using PR 6426 as shown in Figure
4-4 . There is no significant influence on the measuring result in this case.
Installation Guide Installation and Mounting
MHM-97857 January 2020
MHM-97857, Rev 1.5 15