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VibGuy~5

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The latest wireless sensor from CSI has peakvue on one axis only, which I don’t think is a problem, but someone has raised as an issue.

Anybody any thoughts?

MarkL

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Reply with quote  #2 
Not familiar with Csi but if I was using a triaxial sensor I would be happy to have velocity/acceleration on 3 axes and just a high-frequency demod/peakvue in one direction. But just my opinion.
OLi

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Reply with quote  #3 
Yep, that's fine for me too.
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RustyCas

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Reply with quote  #4 
I suspect PeakVue is taken at the primary axis. PeakVue in either of the off-axis sensors would be looking at the mounting point “tangentially”, so basically useless. Stress waves will radiate outward and the primary sensor should be oriented normal to (at a right angle to) the direction where you’d expect to see the highest stress, or the position that gives you the most information for that particular machine.
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MarkL

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Reply with quote  #5 
As Rusty mentioned it should be best in the horizontal direction if possible as on a bigger motor the effectiveness wouldn’t deteriorate
OLi

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Reply with quote  #6 
or axial on most paper machines w/o Carb type brg's.
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fburgos

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Reply with quote  #7 
I use axial peakvue on all my gearboxes (tapered roller bearings) still investigating/trending
Jim Crowe

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Reply with quote  #8 
I don't know about the wireless sensor but the tri-axial accelerometer CSI sells is designed so the axis in line has a higher frequency response. The vertical and axial direction doesn't have a high enough frequency range for Peakvue. I also take a Peakvue on the axial direction on some measurement points but if I were using a tri-axial accel I would orient the accel in the axial direction and not take Peakvue horizontal or vertical.
Curran919

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Reply with quote  #9 
Even if all of the transducers in a triax sensor are designed equivalently such that they have the same free-free natural frequency, the decrease of those natural frequencies due to mounting flexibility is much larger for the secondary axes (x/y) than for the primary axis (z). The z-axis, normal to the mounting surface, will always have the highest mounted natural frequency.

I'd be curious if CSI/Emerson is really designing the primary axis transducers differently from the start...
fburgos

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Reply with quote  #10 
Quote:
Originally Posted by Jim Crowe
I don't know about the wireless sensor but the tri-axial accelerometer CSI sells is designed so the axis in line has a higher frequency response. The vertical and axial direction doesn't have a high enough frequency range for Peakvue. I also take a Peakvue on the axial direction on some measurement points but if I were using a tri-axial accel I would orient the accel in the axial direction and not take Peakvue horizontal or vertical.


Correct, I change acceleration orientation so my axial reading is channel 1/A
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