Holiday Detector Calibration Procedure

This is accomplished by attempting to create an electrical circuit by passing an electrode.

Holiday detector calibration procedure. A holiday is a hole or void in the coating film which exposes the substrate to corrosion. The electrode of the holiday detector which is in the form of a coil spring is put on the surface of the coated pipe. The term holiday dates back to the days of wooden sail ing ships.

Detection mode the detector is generating a high voltage and analyzing electrode voltage and current to determine if holidays are present. Thereafter if necessary procedure of holiday repair to be followed. Holiday testing allows the detection of even smallest coating flaws invisible to the naked eye.

High voltage holiday detector before conducting holiday testing in a confined space or other area where a flammable gas or vapour may be present be sure that proper procedures are followed to thoroughly check and if necessary purge the atmosphere of the work area to prevent the holiday detector from becoming an ignition source. Premature corrosion of a substrate is usually due to a coating failure. Holiday test is used to detect holes known as holidays or discontinuities in a coating.

The user should refer to nace standards rp0274 1 rp0490 2 and or tm03843 for procedures specific to electrical inspection of pipeline coatings. Recommended practice provides a procedure for electrical detection of minute discontinuities in new coating systems that are applied to conductive substrates. 1 1 these test methods cover the apparatus and procedure for detecting holidays in pipeline type coatings.

When in standby the testing procedure. Personnel operating portable holiday detectors should model 785 790 pulse holiday detector will generate radio frequency be aware of the safety limitations imposed by their environment at all times. Electronics or radio equipment.

Unit calibration principles of holiday detector operation holiday detectors are devices that are used to detect the presence of defects in the non conductive coatings applied to surfaces in order to minimize ion ow from a conductive substrate. Unit calibration 1 15 kv for the 785 and 5 35 kv for the 790. A major cause is the presence of flaws in the finished coating collectively referred to as porosity.