ISO INTERNATIONAL 8126 STANDARD Third edition 2019-01 Micrographics - Duplicating film, silver, diazo and vesicular Specifications and measurement for visual density Micrographie - Films de duplication argentiques, diazoiques et vésiculaires Spécifications et mesurage pour la densité visuelle Reference number IS0 8126:2019(E) so @ IS0 2019 IS0 8126:2019(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: copyright@iso.org Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0 8126:2019(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references ..1 3 Terms and definitions ..1 4 Measurement of density ..1 4.1 Method of measurement of silver-gelatin and diazo duplicates 4.2 Method of measurement of vesicular duplicates .2 4.3 Measurement areas... .2 4.3.1 Sampling aperture .2 4.3.2 Use of density patches 2 5 Visual diffuse transmission density of duplicate microforms from source documents and coM .2 5.1 Silver-gelatin duplicates 2 5.1.1 Positive-appearing duplicates. .2 5.1.2 Negative-appearing duplicates .2 5.1.3 Direct positive duplicates. .3 5.2 Diazo duplicates. .3 Projection density of vesicular duplicates. .3 6.1 Vesicular duplicates of source document microforms. 3 6.1.1 Positive-appearing vesicular duplicates of source document microforms .3 6.1.2 Negative-appearing vesicular duplicates of source document microforms .3 6.2 Vesicular duplicates of CoM microforms. ..3 @ IS0 2019 - All rights reserved iii