ISO INTERNATIONAL STANDARD 8672 Second edition 2014-05-01 Air quality Determination of the number concentration of airborne inorganic fibres by phase contrast optical microscopy - Membrane filter method Qualité de I'air - Détermination de la concentration en nombre de fibres inorganiques en suspension dans I'air par microscopie optique en contraste de phase - Méthode du filtre a membrane Reference number IS0 8672:2014(E) @ IS0 2014 IS0 8672:2014(E) COPYRIGHTPROTECTEDDOCUMENT @IS02014 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 Case postale 56 . CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland ii @ IS0 2014 - All rights reserved IS0 8672:2014(E) Contents Page Foreword .iv Introduction. ..V 1 Scope. ..1 2 Normative references ..1 3 Terms and definitions .1 4 General method description .2 4.1 Limitations of the method by particle type 4.2 Limitofvisibilityanddetectionlimits .2 4.3 Apparatus and equipment 3 4.4 Mounting media. .5 4.5 Quality assurance. . 6 5 Sampling. .6 5.1 Flowrate .6 5.2 Acceptable fibre loadings on filters .7 5.3 Storage and transport. .7 5.4 Blanks .7 5.5 Sample duration and volume .8 5.6 Sampling strategy and records .9 6 Evaluation .10 6.1 Sample preparation .10 6.2 Microscopeadjustment principles 11 6.3 Eyepiece graticule calibration .11 6.4 Microscope/counter performance assessment. 11 6.5 Counting and sizing fibres. .12 6.6 Calculation of fibre concentration ..13 7 Sources of errors and uncertainty ..14 7.1 General. ..14 7.2 Uncertainty .14 7.3 Inter-laboratory variability .16 7.4 Lowering of intra- and inter-laboratory variance 17 8 Test report ..17 Annex A (informative) Slide mounting: acetone-triacetin procedure .19 Annex B (informative) Permanent slide preparation: dimethyl formamide - Euparal procedure...21 Annex C (normative) Eyepiece graticule .24 Annex D (informative) Measurement of exposed filter area ..27 Annex E (informative) Microscope adjustment procedure ..28 Annex F (informative) Sources ..29 Bibliography .30 s0.201-. rights reserved iii