ISO INTERNATIONAL STANDARD 7027-2 First edition 2019-01 Water quality - Determination of turbidity - Part 2: Semi-quantitative methods for the Qualité de I'eau - Détermination de la turbidité - Partie 2: Methodes semi-quantitatives pour I'évaluation de la transparence des eaux Reference number IS0 7027-2:2019(E) osi @ IS0 2019 IS0 7027-2:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ IS0 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: +41 22 749 01 11 Fax: +41 22 749 09 47 Email: copyright@iso.org Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0 7027-2:2019(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references ..1 3 Terms and definitions 4 Laboratory .2 4.1 General .2 4.2 Measurement using the transparency testing tube 2 4.2.1 Apparatus.. .2 4.2.2 Sampling and samples 2 4.2.3 Procedure 3 4.2.4 Expression of results. 3 5 In situ methods (field methods) .3 5.1 General 3 5.2 Measurement using the transparency testing disc .3 5.2.1 Apparatus.. .3 5.2.2 Procedure .4 5.2.3 Expression of results. 5 5.2.4 Estimation of the attenuation coefficient (in the marine environment) 5 5.3 Determination of visibility by divers. .5 5.3.1 Apparatus .5 5.3.2 Procedure. ..6 5.3.3 Expression of results .6 6 Test report .6 Annex A (informative) Devices .8 Annex B (informative) Interlaboratory field study results .10 Bibliography ..12 @ IS0 2019 - All rights reserved ii