ISO INTERNATIONAL STANDARD 2178 Third edition 2016-03-15 Non-magnetic coatings on magnetic substrates - Measurement of coating thickness Magnetic method Revetement métalliques non magnétiques sur métal de base magnétique - Mesurage de I'epaisseur du revetement - Méthode maguétique Reference number IS0 2178:2016(E) ISO International Organization for Standardization e=ZHEJIANG INST OF STANDARDIZATION C1 5956617 @IS02016 mitted without license from IHS IS0 2178:2016(E) COPYRIGHT PROTECTED DOCUMENT IS0 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 [email protected] www.iso.org Licensee-ZHEJIANG INST OF STANDARDIzoISQ 6 - All rights reserved networking permited without license from IHS IS0 2178:2016(E) Contents Page Foreword ..V 1 Scope 1 2 Normative references ..1 3 Terms and definitions 4 Principle of measurement ..2 4.1 Basic principle of all magnetic measurement methods. .2 4.2 Magnetic pull-off method 4.3 Magnetic inductive principle 3 4.4 Magnetic flux gauge .5 5 Factors affecting measurement accuracy ..6 5.1 Basic influence of the coating thickness 6 5.2 Magneticpropertiesofthebasemetal ..6 5.3 Electrical properties of the coating materials 7 5.4 Geometry: base metal thickness ..7 5.5 Edge effect. .7 5.6 Geometry: surface curvature .7 5.7 Surface roughness. .8 5.8 Cleanliness: lift-off effect. .8 5.9 Probe pressure. 5.10 Probe tilt. ..8 5.11 Temperature effects ..9 5.12 External electromagnetic fields .9 6 Calibration and adjustment of the instrument .9 6.1 General ..9 6.2 Thickness reference standards ..9 6.3 Methods of adjustment. ..10 7 Measurement procedure and evaluation ..10 7.1 General. ..10 7.2 Number of measurements and evaluation ..11 8 Uncertainty of the results. .11 8.1 General remarks . ..11 8.2 Uncertainty of the calibration of the instrument. ..12 8.3 Stochastic errors... ..13 8.4 Uncertainties caused by factors summarized in Clause 5 13 8.5 ..14 9 Precision .14 9.1 General ..14 9.2 Repeatability (r) ..14 9.3 Reproducibility limit (R) ..15 10 Test report ..15 Annex A (informative) Basic principle of all measurement methods ..17 Annex B (informative) Basic performance requirements for coating thickness gauges which are based on the magnetic method described in this International Standard .19 Annex C (informative) Examples of experimental estimation of factors affecting the measurement ..21 Annex D (informative) Example of uncertainty estimation (see Clause 8) .26 Annex E (informative) Basics of the determination of the uncertainty of a measurement of the used measurement method corresponding to ISO/IEC Guide 98-3 .29 iii icensee=ZHEJIANG INST OF STANDARDIZATION C1 5956617 ted without license from IHS Not for Resale, 2016/6/2 08:34:05