Please share your comments on this article.

Thank you.

http://www.lovejoycontrols.com/lib/TVM_WP.pdf

Hmmm, this is not the first controversial paper ever written by Mr. Lovejoy....

I wonder how it is that people have been balancing large steam and gas turbines for 50 years with proximity probes....

I have actually balanced a few myself...

Isn't that the gentleman who compared vibration analysts to witch doctors a few years back?

Yep that was him...

I can assure you that a rotor bow is visible on both a 3600 rpm and an 1800 rpm unit. Additionally, Absolute probes work. I use proximity probe measurements daily to give me accurate displcement readings to diagnose problems and calculate accurate balance corrections.

Just so we can calibrate the level of underestanding by the author. Have they ever heard of an eccentricity probe or runout compensation?

Error 3…Adding a velocity sensor fixed in line with a proximity probe and subtracting the mount signal from the probe produces an “absolute” vibration signal.

Subtract???...so I've got a casing moving 2 mils at frequency X and an in-line proximity probe moving 3 mils, also at frequency X. Last time I checked the absolute would be 5 mils at that given frequency. You add the vectors, not subtract.

John from PA

What an address lovejoycontrols - Corporate didn't block that name