Reference Standards for NDT

Large Tube EDM4

Since 1973...

PH Tool Reference Standards has been the recognized leader in the manufacture of Reference Standards used in the Non-Destructive Testing (NDT) industry. We are the only company who makes standards, and nothing but standards. As a result, our expertise is second-to-none, as is our commitment to producing the finest notch standards available today. Let’s face it, without professionally manufactured, NIST traceable standards, how reliable are the results of your inspection? In the quality-conscious age we live in, it is increasingly important to trust your critical masters to the company who can deliver on the promise of making “the standards of excellence.”

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Selecting a Reference Standard

To ensure accurate and repeatable inspection, testing equipment must be standardized and calibrated so that data taken by different operators are comparable and can be matched against inspection norms. Selection of a reference standard is determined by testing technique, type of material to be inspected, type of discontinuity to be detected, and any additional application or industry-specific requirements. Reference standards are representative tools designed to ASTM, ASME, AMS, ISO, and many other specifications. They are used to standardize responses from testing equipment. Samples with EDM Notches and Flat-bottom Holes are often used to standardize amplitude of the detected signal with respect to the size and/or position of known reflectors. Side-drilled holes are also an effective target for such standardizations. 

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Preparing a Reference Standard

In cases where reference standards are made from scratch, care needs to be taken to use materials as similar to the component under test as possible. It is often preferable or required to prepare a reference standard from a piece of the same material as that to be tested. This is most often accomplished by introducing EDM notches or machined holes into the actual test object. The advantage of such a reference standard is that the test object and the standard will have the same composition, manufacturing history, surface condition, and geometry.  

In all cases, reference standards must be prepared and used in accordance with well-designed specifications that cover the material selection, the manufacture of artificial defects, and of course, instructions for the specific testing application.