TINKER & RASOR MODEL PD PEARSON DETECTORA. Pearson Type Holiday DetectorThe Tinker & Rasor Pearson type detector was designed to locate discontinuities, flaws or breaks in the coating of buried pipelines. This method makes possible the exact location of coating breaks in buried lines without access to the surface of the coated pipe. Locating electrical discontinuities aids in evaluating the application of a coating and also these discontinuities can be repaired to eliminate corrosion and to reduce the amount of current required for cathodic protection. B. Short LocatorThe apparatus is also effective in locating shorts or undesirable electrical contacts to the buried coated pipe. Such electrical contacts should be removed prior to placing a pipeline under cathodic protection, as these contacts would drain a large amount of protective potential from the coated pipe. C. Pipe LocatorThe apparatus can be used very effectively as a pipe locator on coated pipelines that are electrically connected by a screw or welded joints. This application is particularly effective where it is desired to locate and follow one pipeline along a right-of-way where there are a number of buried lines.