NF EN ISO 21968
NF EN ISO 21968

NF EN ISO 21968

October 2019
Standard Current

Non-magnetic metallic coatings on metallic and non-metallic basis materials - Measurement of coating thickness - Phase-sensitive eddy-current method

This document specifies a method for using phase-sensitive eddy-current instruments for non-destructive measurements of the thickness of non-magnetic metallic coatings on metallic and non-metallic basis materials such as:a) zinc, cadmium, copper, tin or chromium on steel;b) copper or silver on composite materials.The phase-sensitive method can be applied without thickness errors to smaller surface areas and to stronger surface curvatures than the amplitude-sensitive eddy-current method specified in ISO 2360, and is less affected by the magnetic properties of the basis material. However, the phase-sensitive method is more affected by the electrical properties of the coating materials.In this document, the term "coating" is used for materials such as, for example, paints and varnishes, electroplated coatings, enamel coatings, plastic coatings, claddings and powder coatings.This method is particularly applicable to measurements of the thickness of metallic coatings. These coatings can be non-magnetic metallic coatings on non-conductive, conductive or magnetic base materials, but also magnetic coatings on non-conductive or conductive base materials.The measurement of metallic coatings on metallic basis material works only when the product of conductivity and permeability (σ, μ) of one of the materials is at least a factor of two times the product of conductivity and permeability for the other material. Non-ferromagnetic materials have a relative permeability of one.

Main informations

Collections

National standards and national normative documents

Publication date

October 2019

Number of pages

51 p.

Reference

NF EN ISO 21968

ICS Codes

25.220.40   Metallic coatings

Classification index

A91-321

Print number

1

International kinship

ISO 21968:2019

European kinship

EN ISO 21968:2019
Sumary
Non-magnetic metallic coatings on metallic and non-metallic basis materials - Measurement of coating thickness - Phase-sensitive eddy-current method

This document specifies a method for using phase-sensitive eddy-current instruments for non-destructive measurements of the thickness of non-magnetic metallic coatings on metallic and non-metallic basis materials such as:

a) zinc, cadmium, copper, tin or chromium on steel;

b) copper or silver on composite materials.

The phase-sensitive method can be applied without thickness errors to smaller surface areas and to stronger surface curvatures than the amplitude-sensitive eddy-current method specified in ISO 2360, and is less affected by the magnetic properties of the basis material. However, the phase-sensitive method is more affected by the electrical properties of the coating materials.

In this document, the term "coating" is used for materials such as, for example, paints and varnishes, electroplated coatings, enamel coatings, plastic coatings, claddings and powder coatings.

This method is particularly applicable to measurements of the thickness of metallic coatings. These coatings can be non-magnetic metallic coatings on non-conductive, conductive or magnetic base materials, but also magnetic coatings on non-conductive or conductive base materials.

The measurement of metallic coatings on metallic basis material works only when the product of conductivity and permeability (σ, μ) of one of the materials is at least a factor of two times the product of conductivity and permeability for the other material. Non-ferromagnetic materials have a relative permeability of one.

Replaced standards (1)
NF EN ISO 21968
NF EN ISO 21968
December 2005
Standard Cancelled
Non-magnetic metallic coatings on metallic and non-metallic basis materials — Measurement of coating thickness — Phase-sensitive eddy-current method

Table of contents
  • 1 Domaine d'application
  • 2 Références normatives
  • 3 Termes et définitions
  • 4 Principe de mesure
  • 5 Facteurs influant sur l'incertitude de mesure
  • 6 Étalonnage et ajustage de l'instrument
  • 7 Mode opératoire de mesurage et évaluation
  • 8 Incertitude des résultats
  • 9 Fidélité
  • 10 Rapport d'essai
  • Annexe A Production de courants de Foucault dans un conducteur métallique
  • Annexe B Principes de base de la détermination de l'incertitude de mesure de la méthode de mesure utilisée correspondant au Guide ISO/IEC 98-3
  • Annexe C Exigences de performance de base des jauges d'épaisseur de revêtement fondées sur la méthode par courants de Foucault sensible aux variations de phase décrite dans le présent document
  • Annexe D Exemples d'estimation expérimentale des facteurs qui affectent l'exactitude de mesure
  • Annexe E Tableau de la variable de Student
  • Annexe F Exemple d'estimation de l'incertitude
  • Annexe G Détails relatifs à la fidélité
  • Bibliographie
ZOOM ON ... the Requirements department

To comply with a standard, you need to quickly understand its issues in order to determine its impact on your activity.

The Requirements department helps you quickly locate within the normative text:

  • mandatory clauses to satisfy,
  • non-essential but useful clauses to know, such as permissions and recommendations.

The identification of these types of clauses is based on the document "ISO/IEC Directives, Part 2 - Principles and rules of structure and drafting of ISO documents" as well as on a constantly enriched list of verbal forms.

With Requirements, quickly access the main part of the normative text!


What is the Redline format?
New: UPSELL service
Need to identify, monitor and decipher standards?