UT sound dampening through paint

Date 11-12-2008 23:57

...I am attempting to get the specs on the paint and the design mils so i can copy the in situation product into a calibration proceedure...

If this means you are going to have the calibration standard (or a mock-up) painted, yes I have had this done. Just make sure your procedure is written by a Level III and your customer or EOR approves it. Also, use a coating thickness gage on each joint, and document the DFT readings on your report. We generally have an additional charge for a new calibration block or mock-up as they will require blasting, priming and painting (or coating).

~thirdeye~

By NDTIII

Date 11-18-2008 20:10

If you paint your cal block with the same type of paint you should be ok. Alternatively you can use a transfer correction technique. Use a shear wave probe with a blank wedge or a trhough transmission setup and note the dB difference between the calibration block and the part being inspected and compensate for it.

By hogan

Date 11-18-2008 21:43

NDTIII,
In addition to transfer, won't the beam change it's angle going through the paint?

By NDTIII

Date 11-19-2008 12:51

Possibly but most likely not significantly. Depends on the thickness of the paint. You can check that as well.

By hogan

Date 11-20-2008 14:42

NDTIII,
This is something that I have not had the opportunity to experiment with in the past. Snell's law tells us that it will happen. If you have would you mind sharing what you came up with?