Message Board Thread - "Airborne Ultrasound"

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Airborne Ultrasound Eddie Hindmarsh 5/19/2004
I have recently started to carry out airborne ultrasound checks along with my thermographic surveys using an Ultraprobe10000. I am assured that tracking/arcing can be detected within OCB,. and in cable boxeseven if they are filled with compound. I survey many 11kv. substations but have found nothing yet, but maybe there was nothing to find. Has anyone else detected this type of problem
Eddie Hindmarsh
ephindma@zamnet.zm
 
Re:Airborne Ultrasound Mark G 5/26/2004
It is a great idea to combine the use of IR with Ultrasound, as there are times when there is not a direct line of sight for the IR to "see" anything. That is where Ultrasound can be of help. You can use the Scanning or Airborne Sensor to detect any problems on external components and on internal components when there is a vent or opening (pathway)that the "vibrating" molecules can penetrate. If the item under examination is sealed, then the Contact Module can be used to detect the structure borne Ultrasound generated within. Sometimes there is ultrasound being generated and detected, but the Inspector does not know what the signature means. As most IR Inspectors have more and more items to scan, Ultrasound can be used to supplement the IR Scans and do a more frequent check of critical components to avoid costly shutdowns. Any suspect signatures can be recorded for further analysis. This can be done with spectrum analysis of the wave files.

I would be more than happy to email representative Electrical wave files and spectrums to anyone that needs them.
 
Re:Airborne Ultrasound Jim Hall 1/4/2005
OCB cabinets especially with compound fill are extremely hard to define arcing and tracking. However, your best "bet" is the contact probe or magnetic mount sensor.
Also, keep in mind when scanning with airborne ultrasound you may experience sound of corona and you may see a thermal signature. Some specialist also feel that as corona moves toward arcing and tracking (within the 300-400 namometers range)a thermal signature may be seen. I have personally experienced this in a substation.
When using your ultrasound device remember to create wave files.
Be familiar with the sounds or corona, arcing and tracking as well as what to look for in Spectra and Time Seies...
 

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