ASTM E 309

1.1 This practice covers a procedure for applying the eddy-current method to detect discontinuities in ferromagnetic pipe and tubing (Note 1) where the article being examined is rendered substantially non-magnetic by the application of a concentrated, strong magnetic field in the region adjacent to the examining coil. Note 1 -For convenience, the term tube or tubular product will hereafter be used to refer to both pipe and tubing. 1.2 The procedure is specifically applicable to eddy-current testing methods using an encircling-coil assembly. However, eddy-current techniques that employ either fixed or rotating probe-coil assemblies may be used to either enhance discontinuity sensitivity on the large diameter tubular products or to maximize the response received from a particular type of discontinuity. 1.3 This practice is intended for use on tubular products having outside diameters from approximately <(hoch)1>/<(Index)4> to 10 in. (6.35 to 254.0 mm). These techniques have been used for smaller and larger sizes however, and may be specified upon contractual agreement between the purchaser and the supplier. 1.4 This practice does not establish acceptance criteria; they must be specified by the using party or parties. 1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.