Recently , i came across an acoustic emission meter from Holoroyd, which can detect gas and steam leaks through ultrasound as well as can detect incipient bearing problems, such as boundary lubricating conditions. It has absolute values of distress defined in terms of dB which tells the health of bearings. Anyone , more conversant with this technology may pl. advice if it is worth the bucks spent , if they have used it. I am not very much conversant with distress values for bearings.
Regards.

I have been using Holroyd's Memo-Pro for about 6 years now. The instrument is fairly decent for detecting bearing problems, but not as good as it is made out to be. DISTRESS value can be highly affected by any impacts or rubs, including those that happen in normal running.

Conversely, I have seen cases where severe impacts are evident in the vibration time waveform & BPFO/BPFI peaks evident in the velocity spectrum, but DISTRESS as low as 7-8. I have spoken with other Holroyd users, they too felt that Holroyd is better suited for speeds below 1000 RPM, vibration is better for higher speed machines.

The good part of the Holroyd products is the heterodyned headphone output. Excellent for figuring whether the problem lies in the bearing or the lubrication. Also, good for really slow speed machines below 100 RPM. You need to use the Peak, Intensity & Extent measurements though, not DISTRESS.

Regards,

Aditya

Do you currently not have any instrument such as a vibration data collector to check for bearing faults. If no, then an ultrasonic device can be used. It would not be my first choice, but if you do not have a lot of money to spend then it may be the way to go.

Regards,

quote:

Originally posted by Mick3040:
Do you currently not have any instrument such as a vibration data collector to check for bearing faults. If no, then an ultrasonic device can be used. It would not be my first choice, but if you do not have a lot of money to spend then it may be the way to go.

Regards,

Currently I have got vibration pen which catches enveloped acceleration and Comtest make Vb 1000. Both are good and handy. Vibration pen is meant for trending enveloped accln wihtout any threshold values indicating danger or alert whereas Holoroyd acoustic emission meters give distress values with threshold. Of course, we can go for demodulation data with Vb 1000 but this is an specialised instrument not fit for technicans.

Personally I would use the Commtest meter over the other stuff for bearing detection! I would recommend learning how to use it if you don't already.

Regards,

Akhtar
Aditya has hit the nail on the head, the memo pro is good but for anything over 120rpm I would use shock pulse and vibration. I have a memo pro and it is used to complement my CBM scheme not be the only tool in the box. If money is tight you can get a small plug in device for a pocket pc relativly cheaply with ok software that is easy to use. This is what I did to get the boys with the money interested in buying me one of the better models.