14:55 May-25-2009 Abbas Bombaywala NDT Inspector, Free Lance, India, Joined Jul 2007 83
Corrosion Mapping Calibration Block & Standards
I want to know that are there any special codes and standard for Corrosion mapping or we have to just use the Asme Sec V article 4 for Manual UT, Is there any standard calibration block for Corrosion mapping,
How about if we can make one of our own calibration blocks with FBH of 1 mm & 2 mm dia with the different depth simulating the different percentage loss. for example for 10 mm plate 1 mm & 2 mm dia FBH with different depths from 50 % to 90 % of the thickness. Can we make this type of calibration block and prove the sensitivity.
Quick & Prompt reply will be highly appreciated
01:57 May-28-2009 Mark Nel , Applications Advisor, Technology Design Ltd., United Kingdom, Joined Jul 2005 46
Abbas, As corrosion mapping is an in service inspection and is usually requested as part of the wider corrosion control effort, it is to my knowledge rarely approached from a strict regime controlled by a specification but rather a procedure or technique is established based on the corrosion mapping equipment manufacturers particular method of applying this procedure in his hardware/software and configuring these to conform with the corrosiom department/engineers requirements. This department or individual quite often even looks to the service provider to supply the procedure for the task. There may even be several alternatives that you could choose from to best complete the task. Although, I guess there's nothing wrong with making a block with artificial defects to qualify the procedure, remember that all you really are doing is measuring thickness and translating these wall thickness readings into a colour-graphic image that provides an excellent means of identifying trends. The actual data may also be interrogated in minute detail using the available software tools (cursors etc.) to provide specific depth readings of each recorded area (pixel). I suggest that you contact the equipment vendor, as suggested by a previous respondent, to get a step-by-step guide on how to configure system for corrosion mapping.