GPTI – GROUP OF COMPANIES
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+971 6 568 2435
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+971 52 608 5790
An ISO Management system certified company ISO 9001 / ISO 14001 / ISO 45001
An ISO/IEC-17020 Certified Inspection Body. EIAC Certificate No.IB-167
The particular liquid penetrant, usually a red dye or a fluorescent dye using a black light, is applied to generally non-ferrous materials. It is also advantageous to use a low sulphur and halogen dye. The area to be tested must be clean.
The dye is applied and left for approximately ½ an hour or longer on the surface which enables the dye to be drawn by capillary action, into a surface breaking indication. The excess dye is removed by either water or solvent soaked cloth and developer is applied, a further waiting period of upto approximately 15 minutes or longer is required where the coloured dye will contrast with the white developer enabling the technician to identify any discontinuities.
The magnetic field can be introduced into the test specimen by either direct or indirect magnetization. Direct magnetization occurs when the electric current is passed through the test object and a magnetic field is formed in the material. Indirect occurs when no current is passed through the test specimen, but a magnetic field is applied from the outside source. When the magnetic field is disturbed by surface or near-surface discontinuities the magnetic powder forms around an indication which can be seen quite clearly.
