BS EN 12084:2001 – This is an uncontrolled copy. Ensure use of the most current version of this document by searching British Standards Online at bsonline.techindex.co.uk

1 Scope
This standard defines the general principles to be applied to the eddy current non-destructive examination of products and materials in order to provide a defined and repeatable performance.
It includes guidelines for the preparation of application documents, which describe the specific requirements for the application of the eddy current method to a product.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments).
EN 473, Qualification and certification of NDT personnel – General principles.
EN 1330-5, Non-destructive testing – Terminology – Part 5 : Terms used in Eddy Current testing.
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions given in EN 1330-5 apply.
4 General principles
The eddy current examination is based upon the induction of an electric current in a conducting material. The quantity measured and analysed is related to the distribution of the induced currents. For alternating excitation it is represented by a vector in the complex plane.
The distribution of eddy current in material depth is governed by physical laws; the density of these currents decreases drastically with increasing depth. For high frequency excitation, this decrease is an exponential function of depth.
The basic parameters which influence the measured quantity are all of the following properties of the product to be tested, alone or in combination :
the conductivity of the material ;
the magnetic permeability of the material ;
the size and geometry of the product to be tested ;
the geometry between the eddy current probe and the product to be tested.
More detailed information is obtained when the measured quantity is displayed in the complex plane.
The following characteristics of the method can be used to advantage :
it can be used without making physical contact with the product ;
it does not need a coupling medium such as water ;
it is capable of being used at high throughput speeds.
BS EN 12084:2001 – This is an uncontrolled copy. Ensure use of the most current version of this document by searching British Standards Online at bsonline.techindex.co.uk