ISO INTERNATIONAL STANDARD 20146 First edition 2019-01 Vacuum technology Vacuum gauges Specifications, calibration and measurement uncertainties for capacitance diaphragm gauges Technique du vide-Manometres a vide-Spécifications, étalonnage etincertitudesdemesuredesmanometrescapacitifsamembrane Reference number IS0 20146:2019(E) Tso IS02019 IS0 20146:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ ISO 2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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 CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +4122 749 0111 Fax: +41 22 749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0 20146:2019(E) Contents Page Foreword ..V Introduction. ...vi 1 Scope. 2 Normative references 3 Terms and definitions 3.1 Components. ..1 3.2 Physical parameters 3.3 Other parameters.. .4 4 Symbols and abbreviated terms ..6 5 Capacitance diaphragm gauge .6 5.1 Principle. ..6 6 Specifications for capacitance diaphragm gauge 6.1 Type of capacitance diaphragm gauge .1 6.2 Temperature control of gauge head. 6.3 Display and measurement signal output unit. 7 6.4 Measurement range of capacitance diaphragm gauge .7 6.5 Expected measurement uncertainty 7 6.6 Temperature coefficients of zero readings and span .7 6.7 Resolution. .7 6.8 Response time of the gauge head. 1 6.9 Warm-up period .8 6.10 Admissible pressure (maximum load pressure) ..8 6.11 Disruption pressure (burst pressure). 6.12 Materials exposed to gas ..8 6.13 Mounting orientation of the gauge head ..8 6.14 Fitting to chamber.. ..8 6.15 Internal volume. ..8 6.16 Interface and pin connections ..8 6.17 Compatibility between a gauge head and a control unit .8 6.18 Dimension and weight of the gauge head and control unit ..8 6.19 Nominal operating (environmental) conditions. .8 6.20 Storage and transportation condition. .9 6.21 Input power and its requirements. .9 7 Additional (optional) specifications for capacitance diaphragm gauge .9 7.1 Reproducibility (long-term instability) ..9 7.2 Tilting effect on zero readings. .9 7.3 Repeatability of zero ..9 7.4 Durability of zero after the pressure of full scale 9 7.5 Durabilityofspanafterthepressureoffullscale .9 7.6 Durability of zero after the admissible pressure.. .9 7.7 Durability of span after the admissible pressure. .10 7.8 Update interval .10 7.9 Inner diameter of connecting tube .10 7.10 Cablelength .10 7.11 Set point of pressure. .10 7.12 Photographs .10 7.13 Inspection record and calibration certificate ..10 Calibration ..10 8 8.1 Calibration procedure .10 8.2 Calibration uncertainty. .11 8.3 Calibration certificate. .11 @ IS0 2019 - All rights reserved iii