WHAT DOES PHASE MEANS IN A SCREEN OF non destructive test terminology?

Question

phase in eddy current,and pips in ultrasonic

Answer 1

ND TL used in metallurgical testing in heavy engineering like power plant equipment, Non - Destructive mean without destructing the given material pipe joint or pressure parts testing. example- Die penetration test, X'rays., Eddy current test & Ultrasonic flaw detector.you ask about eddy current for testing a welded joint using high current Dc pass thro two probes between welded joint result a strong magnetic field will set up in between the probes a fine metal powder sprayed on that area, because of eddy current effect the pattern formed by metal powder will be different if there is a crack on it, with that Inspector identifies the deffective area mark it for further repairing .with this invisible crack can be found .

Ultrasonic testing means - it is a portable appratus with a monitor screen with high frequency crystal probes are used to find the deffect in welded metal (pulse echo technique)high frequency pass thro metal pulse will end up to the end of the metal ie is the thickness if there any crack on it it will return earlier the time dfference will be shown the crack on which area of depth.Test pices are available to check the equipment calibration.I hope I have given you little idea you want further more pm me