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909 views
07:59 Jun-28-2007
kevin whinney
eddy current

Is it ok to do eddy current on pad eye fitted to decks

at this time we use MPI but removing the coating is becoming a problem with the client

He has said he has see eddy current used thought the coating
but when i have looked in to this there is test probs made for thought coating but to calibrate the eddy current tester you need to know the coating thickness

please if any one is doing inspection of pad eye using eddy current then any information would bee nice


 
00:12 Jun-28-2007

Joe Buckley

Consultant, ASNT L-III, Honorary Secretary of BINDT
Level X NDT, BINDT,
United Kingdom,
Joined Oct 1999
509
Re: eddy current Its not really a problem - the approach recommended in EN1711 is to use an absolute eddy current probe to measure the coating thickness and then calibrate accordingly. another approach nowadays would be to use a digital coating thickness gauge.

You only need to know the coating thickness to use enough gain to ensure you find the equivalent defects . absolute accuracy is not necessary.

Joe

---------- Start Original Message -----------
: Is it ok to do eddy current on pad eye fitted to decks
: at this time we use MPI but removing the coating is becoming a problem with the client
: He has said he has see eddy current used thought the coating
: but when i have looked in to this there is test probs made for thought coating but to calibrate the eddy current tester you need to know the coating thickness
: please if any one is doing inspection of pad eye using eddy current then any information would bee nice
------------ End Original Message ------------




 
01:36 Jun-29-2007

Neil Burleigh

Sales
Krautkramer Australia Pty Ltd,
Australia,
Joined Dec 2002
146
Re: eddy current Yes what Joe has said is all true but the coating thickness can vary over the inspection area so it would be better to be able to monitor the coating thickness during inspection and then adjust the sensitivity as required. A dual frequency EC inspection using a weldscan probe would do just that.
There was an interesting technical paper given at the Asia Pacific Conference of NDT in New Zealand last year on dual frequency EC inspection of coated welds which discussed this topic.
Also another helpful hint is to cover the inspection area with a thin clear plastic sheet, like OHP film, because the painted surface is generally very rough, anti-slip paint, and this will reduce wear on the weldscan probe. Plus you will also have a '1:1 drawing' of your inspection.
Hope this helps
Regards
Neil
----------- Start Original Message -----------
: Its not really a problem - the approach recommended in EN1711 is to use an absolute eddy current probe to measure the coating thickness and then calibrate accordingly. another approach nowadays would be to use a digital coating thickness gauge.
: You only need to know the coating thickness to use enough gain to ensure you find the equivalent defects . absolute accuracy is not necessary.
: Joe
: ---------- Start Original Message -----------
: : Is it ok to do eddy current on pad eye fitted to decks
: : at this time we use MPI but removing the coating is becoming a problem with the client
: : He has said he has see eddy current used thought the coating
: : but when i have looked in to this there is test probs made for thought coating but to calibrate the eddy current tester you need to know the coating thickness
: : please if any one is doing inspection of pad eye using eddy current then any information would bee nice
------------ End Original Message ------------




 
07:31 Jul-02-2007
Steve Greenall
Re: eddy current Hi Kevin,

Our equipment is designed exactly for through coating inspections and has been utilised in this way for years. We have a lift off compensation which means you can inspect without having to worry about coating thickness or inputting guestimate coating thicknesses into the equipment(which are invariably wrong for the reasons Neil mentioned.)

Please have a look at our products here
http://www.lizard.co.uk/products/products.html
and feel free to email me with any questions

Steve

----------- Start Original Message -----------
: Is it ok to do eddy current on pad eye fitted to decks
: at this time we use MPI but removing the coating is becoming a problem with the client
: He has said he has see eddy current used thought the coating
: but when i have looked in to this there is test probs made for thought coating but to calibrate the eddy current tester you need to know the coating thickness
: please if any one is doing inspection of pad eye using eddy current then any information would bee nice
------------ End Original Message ------------




 


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