IEC 62812:2019

Low resistance measurements - Methods and guidance

IEC 62812:2019 specifies methods of measurement and associated test conditions that eliminate or reduce the influence of adverse phenomena in order to improve the attainable accuracy of low-resistance measurements. The methods described in this document are applicable for the individual measurements of the resistance of individual resistors, and also for resistance measurements as part of a test sequence. They are applied if prescribed by a relevant component specification, or if agreed between a customer and a manufacturer.
The contents of the corrigendum of March 2020 have been included in this copy.

Mesures de faibles résistances - Méthodes et recommandations

L'IEC 62812:2019 spécifie les méthodes de mesure et les conditions d'essai associées qui éliminent ou réduisent l'influence des phénomènes défavorables afin d'améliorer la précision réalisable des mesures de faibles résistances. Les méthodes décrites dans le présent document s'appliquent aux mesures individuelles de la valeur de résistances individuelles, ainsi qu'aux mesures de résistances dans le cadre d'une séquence d'essai. Elles sont appliquées si elles sont prescrites par une spécification de composant pertinente ou si elles font l'objet d'un accord entre un client et un fabricant.
Le contenu du corrigendum de mars 2020 a été pris en considération dans cet exemplaire.

General Information

• Status: Published
• Publication Date: 01-May-2019
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 31.040.01 - Resistors in general
• Technical Committee: TC 40 - Capacitors and resistors for electronic equipment
• Drafting Committee: PT 62812 - TC 40/PT 62812
• Current Stage: PPUB - Publication issued
• Start Date: 24-May-2019
• Completion Date: 02-May-2019

Relations

• Corrected By: IEC 62812:2019/COR1:2020 - Corrigendum 1 - Low resistance measurements - Methods and guidance
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 62812 ®
Edition 1.0 2019-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low resistance measurements – Methods and guidance

Mesures de faibles résistances – Méthodes et recommandations

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IEC 62812 ®
Edition 1.0 2019-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low resistance measurements – Methods and guidance

Mesures de faibles résistances – Méthodes et recommandations

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.040.01 ISBN 978-2-8322-6870-4

– 2 – IEC 62812:2019 © IEC 2019
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Resistance measurement phenomena . 7
4.1 General . 7
4.2 Lead and contact resistance . 7
4.3 Self-heating . 9
4.4 Variation of resistance with temperature . 10
4.5 Thermoelectric e.m.f. . 12
4.6 Peltier effect . 15
5 Methods of measurement . 16
5.1 General . 16
5.2 Four-wire resistance measurement . 16
5.3 Offset compensation method . 19
5.4 Current inversion method . 22
5.5 Differential current inversion method . 25
5.6 Short-term trigger method . 28
6 Connecting the specimen . 32
6.1 Resistors with lead wires for soldered assembly . 32
6.1.1 Connecting leaded resistors in a test fixture . 32
6.2 Resistors with solder terminations for surface mount assembly . 33
6.2.1 Connecting SMD resistors on a test substrate. 33
6.2.2 Connecting SMD resistors in a test fixture . 35
7 Information to be given in the relevant component specification . 36
Annex A (normative) Letter symbols and abbreviated terms . 37
A.1 Letter symbols . 37
A.2 Abbreviated terms . 38
Annex B (informative) Test results of soldering pad with Kelvin connection for surface
mount resistors . 39
B.1 General . 39
B.2 Test procedures . 39
B.2.1 Test substrates . 39
B.2.2 Test method . 41
B.3 Measurement result and studies . 42
Bibliography . 45

Figure 1 – Resistance measurement using two-wire sensing . 8
Figure 2 – Variation of resistance with temperature (random example) . 10
Figure 3 – Resistances on a resistor with lead wires . 11
Figure 4 – SMD chip resistor on a PCB . 12
Figure 5 – Thermoelectric e.m.f. . 13
Figure 6 – Thermocouples on a resistor with lead wires . 14
Figure 7 – Resistance measurement affected by thermoelectric e.m.f. . 15

Figure 8 – Four-wire resistance measurement . 17
Figure 9 – Offset compensation method for resistance measurement . 19
Figure 10 – Current and voltage in the offset compensation method . 20
Figure 11 – Current inversion method for resistance measurement . 22
Figure 12 – Current and voltage in the current inversion method . 23
Figure 13 – Current and voltage in the differential current inversion method . 26
Figure 14 – Example of resistor specimen. 31
Figure 15 – Connecting leaded resistors in a test fixture . 32
Figure 16 – Resistance of cylindrical copper lead wires . 33
Figure 17 – Soldering pad of test substrate for Kelvin (four-point) connections . 34
Figure 18 – Resistance of PCB conductor tracks with 35 µm copper thickness. 35
Figure 19 – Example for connecting SMD resistors on a test fixture . 36
Figure B.1 – Lengths of soldering pad . 40
Figure B.2 – Position of voltage sense conductor . 40
Figure B.3 – Thickness of the solder printing screen and position of sense line . 43
Figure B.4 – Position of voltage-sensing line. 43
Figure B.5 – Soldering pad length . 44
Figure B.6 – Recommended soldering pad . 44

Table 1 – Relative Seebeck coefficients of selected metals. 13
Table A.1 – Letter symbols . 37
Table B.1 – Thickness of solder printing screen . 41
Table B.2 – Table of test conditions . 42

– 4 – IEC 62812:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW RESISTANCE MEASUREMENTS –
METHODS AND GUIDANCE
FOREWORD
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