SIST EN 4875:2020

Aerospace series - Surface treatments - Test method for measurement of electrical contact resistance

This document describes the electrical contact resistance testing method applicable to conductive and non-conductive coatings applied on test specimens made of conductive materials (unless otherwise specified) for aerospace applications. An objective of this practice is to define and control many of the known variables in such a way that valid comparisons of the contact properties of materials can be made.
This test may be locally destructive depending on the process tested.

Luft- und Raumfahrt - Oberflächenbehandlungen - Prüfverfahren zur Messung von elektrischer Kontaktwiderstand

Dieses Dokument beschreibt das Verfahren zur Prüfung des elektrischen Kontaktwiderstands, das für leitfähige und nicht leitfähige Beschichtungen gilt, die auf Prüfkörper aus leitfähigem Material (sofern keine anderslautenden Festlegungen bestehen) für Anwendungen in der Luft- und Raumfahrt aufgebracht werden. Ziel dieser Praxis ist es, viele der bekannten Variablen so zu definieren und zu steuern, dass gültige Vergleiche der Kontakteigenschaften von Materialien möglich sind.
Diese Prüfung kann je nach dem geprüften Prozess lokal zerstörend sein.

Série aérospatiale - Traitements de surface - Méthode de mesure de la résistance électrique de contact

Le présent document décrit la méthode d’essai de mesure de la résistance électrique de contact destinée aux revêtements conducteurs ou non conducteurs appliqués sur des éprouvettes d’essai en matériaux conducteurs (sauf spécification contraire) pour les applications aérospatiales. Cette pratique a pour objectif de déterminer et contrôler bon nombre des variables connues de telle sorte que des comparaisons pertinentes des propriétés de contact des matériaux puissent être effectuées.
Cet essai peut être partiellement destructif en fonction du procédé soumis à essai.

Aeronavtika - Površinske prevleke - Preskusna metoda za merjenje električne kontaktne upornosti

Ta dokument opisuje metodo za preskušanje električne kontaktne upornosti, ki se uporablja za prevodne in neprevodne prevleke, nanesene na preskusne vzorce iz prevodnih materialov (razen če je določeno drugače) za uporabo v aeronavtiki. Cilj te prakse je določiti in nadzorovati številne znane spremenljivke na ta način, da je mogoče izdelati veljavne primerjave kontaktnih lastnosti materialov. Ta preskus je lahko lokalno uničevalen, odvisno od preskušanega procesa.

General Information

• Status: Published
• Publication Date: 21-Jan-2020
• ICS: 25.220.99 - Other treatments and coatings
• ICS: 49.040 - Coatings and related processes used in aerospace industry
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 16-Jan-2020
• Due Date: 22-Mar-2020
• Completion Date: 22-Jan-2020
• Ref Project: EN 4875:2020 - Aerospace series - Surface treatments - Test method for measurement of electrical contact resistance

Overview

SIST EN 4875:2020 is a European standard developed by CEN that specifies the test method for measuring electrical contact resistance of surface treatments in aerospace applications. It covers both conductive and non-conductive coatings applied on conductive substrates. The standard aims to provide a controlled, reproducible procedure to evaluate contact resistance properties, allowing for valid comparisons between different coatings and materials.

This standard is essential for aerospace manufacturers and suppliers who need to verify electrical contact quality of surface coatings, ensuring performance and reliability in critical aerospace components. It applies to treated specimens typically made from conductive materials and involves standardized testing under defined electrical and mechanical conditions.

Key Topics

• Scope and Application: Applicable to aerospace industry coatings on conductive materials. Provides a method to measure electrical contact resistance, crucial for optimizing electrical performance in aerospace surface treatments.

• Test Principle: Measures electrical resistance by applying a known current and measuring the voltage drop across the test specimen. Resistance is calculated using Ohm’s law.

• Test Specimens: Recommended size is 100 mm x 250 mm with a minimum thickness of 1 mm. Both faces of the specimen are tested. Surface roughness and preparation directly impact results.

• Testing Equipment: Uses calibrated ohmmeters or multimeters with appropriate ranges. Electrodes must be copper or pure silver-plated copper, polished to a mirror finish to ensure accurate contact.

• Measurement Procedure: Includes controlled pressure (per process specifications), stable test current at 1.0 ± 0.1 A, and ambient conditions between 15 °C – 35 °C with humidity below 70%. Measurements exclude edges and damaged areas to maintain consistency.

• Data Reporting: Results are expressed in resistance per surface unit and require multiple measurements for statistical reliability. Test reports must document all relevant variables including specimen details, electrode type, pressure, and any deviations from the standard.

• Destructiveness: The test may be locally destructive depending on the coating and test conditions.

Applications

SIST EN 4875:2020 is widely used across aerospace industry sectors for:

• Quality Control: Ensures coated aerospace components meet electrical contact resistance criteria to guarantee functionality in electrical grounding, bonding, and shielding systems.

• Process Qualification: Helps validate surface treatment processes and coatings, confirming that contact resistance performance aligns with aerospace specifications.

• Material Comparison: Allows aerospace engineers to compare electrical performance of different coatings or substrate materials under standardized conditions.

• Failure Analysis: Identifies issues related to coating degradation or improper surface treatment affecting electrical conductivity.

• Supplier Verification: Supports manufacturer audits and supplier quality inspections by providing consistent measurement procedures agreed upon industry-wide.

Related Standards

• While SIST EN 4875:2020 has no direct normative references, it complements other aerospace surface treatment and coating standards such as those governing corrosion protection, adhesion testing, and coating thickness measurement.

• Related aerospace standards might address coating specifications, environmental testing, and electrical system design pertinent to grounding and bonding-areas where electrical contact resistance is critical.

• International standards on electrical resistance measurement methods and surface treatment (ISO, IEC) provide terminology and fundamental concepts referenced within SIST EN 4875:2020.

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Keywords: SIST EN 4875:2020, electrical contact resistance, aerospace surface treatments, conductive coatings, non-conductive coatings, aerospace testing method, aerospace coatings quality control, contact resistance measurement, surface treatment standards, aerospace materials testing.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2020
Aeronavtika - Površinske prevleke - Preskusna metoda za merjenje električne
kontaktne upornosti
Aerospace series - Surface treatments - Test method for measurement of electrical
contact resistance
Luft- und Raumfahrt - Oberflächenbehandlungen - Prüfverfahren zur Messung von
elektrischer Kontaktwiderstand
Série aérospatiale - Traitements de surface - Méthode de mesure de la résistance
électrique de contact
Ta slovenski standard je istoveten z: EN 4875:2020
ICS:
25.220.99 Druge obdelave in prevleke Other treatments and
coatings
49.040 Prevleke in z njimi povezani Coatings and related
postopki, ki se uporabljajo v processes used in aerospace
letalski in vesoljski industriji industry
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 4875
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2020
EUROPÄISCHE NORM
ICS 25.220.99; 49.040
English Version
Aerospace series - Surface treatments - Test method for
measurement of electrical contact resistance
Série aérospatiale - Traitements de surface - Méthode Luft- und Raumfahrt - Oberflächenbehandlungen -
d'essai de mesure de la résistance électrique de contact Prüfverfahren zur Messung von elektrischer
Kontaktwiderstand
This European Standard was approved by CEN on 11 November 2019.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 4875:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 4
5 Apparatus. 4
6 Test specimen . 5
7 Procedure . 6
8 Results of electrical contact resistance . 8
9 Designation . 8
10 Test report . 8

European foreword
This document (EN 4875:2020) has been prepared by the Aerospace and Defence Industries Association
of Europe — Standardization (ASD-STAN).
After enquiries and votes carried out in accordance with the rules of this Association, this Standard has
received the approval of the National Associations and the Official Services of the member countries of
ASD, prior to its presentation to CEN.
This document shall be given the status of a national standard, either by publication of an identical text
or by endorsement, at the latest by July 2020, and conflicting national standards shall be withdrawn at
the latest by July 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
1 Scope
This document describes the electrical contact resistance testing method applicable to conductive and
non-conductive coatings applied on test specimens made of conductive materials (unless otherwise
specified) for aerospace applications. An objective of this practice is to define and control many of the
known variables in such a way that valid comparisons of the contact properties of materials can be made.
This test may be locally destructive depending on the process tested.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
 ISO Online browsing platform: available at http://www.iso.org/obp
 IEC Electropedia: available at http://www.electropedia.org/
3.1
contact resistance
resistance to current flow between two touching bodies, consisting of constriction resistance and film
resistance
4 Principle
The principle of the method involves applying a known current I to the coating, measuri
...