Pulsed Eddy Current (PEC) is a nondestructive examination technique used for detecting flaws or corrosion in ferrous materials or measuring the thickness of objects. PEC is an electromagnetic inspection technique used to detect wall loss on ferromagnetic structures such as carbon steel and cast iron. It provides a relative volumetric measurement converted into an averaged thickness measurement based on the calibration area.
Clev Dynamic offers Pulsed Eddy Current (PEC) inspection technology for the detection of corrosion
areas in carbon and low alloy steels. Measurements are taken through any non-conductive material
e.g., insulation, protective coatings, concrete and marine growth.
PEC works using the principle of electromagnetic induction. When applying step function voltage to a conductor, a magnetic field develops around it. This field changes in intensity as the current alternates. If brought close to the first field, another conductor will have a current induced in it as well. If there are any flaws in this material then the eddy current will distort. In the case of PEC, the first conductor is an eddy current probe. The second is the test material.
The main advantage of PEC over conventional eddy current is that it contains a continuum of frequencies. Because of this, it is possible to measure the electromagnetic response to several different frequencies can with just a single step. Information from a range of depths can be obtained all at once.
PEC obtains a measure of the wall thickness by taking an average reading over the probe’s footprint (the roughly circular area where eddy currents flow). This makes it ideal for measuring general wall loss.
Using the PEC inspection technique offers a variety of benefits, including:
- No interference with production. PEC technology can be applied in-service, so there is no need to empty storage spheres.
- No need to remove the passive fire protection. PEC technology can measure through up to 250 mm of material including the reinforcement mesh.
- Performed in service during plant operation
- Accessibility issues are minimized as it can be used by rope access operators.
PEC can be done without need for contact with the surface of the material. Because of this, it can be useful in situations where an object’s surface is rough or inaccessible. This method also doesn’t require surface preparation or removing any insulation. It can be a quick and cost-effective solution for corrosion detection.
PEC is widely used for a number of applications. These include both measuring the thickness of steels and detecting corrosion. It can be used on materials as diverse as vessels, columns, storage tanks and spheres, piping systems, and structural applications with fireproofing. Furthermore, it can be used on both insulated and uninsulated materials.
Clev Dynamic Inspections Limited understands the need for high operator proficiency in order to get the best results from PEC and so, all of our Inspectors receive ongoing training and are experienced in the field. Contact us today for more information or quotation.