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1、BRITISH STANDARD BS EN ISO 787-23:1995 Incorporating Amendment No. 1 General methods of tests for pigments and extenders Part 23: Determination of density (using a centrifuge to remove entrained air) The European Standard EN ISO 787-23:1995 has the status of a British Standard ICS 87.060.10; 87.060.
2、80 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:56:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 787-23:1995 This British Standard, having been prepared under the direction of the Pigments, Paints and Varnishes Standards Committee, was published under the authority of the Exec
3、utive Board and comes into effect on 31 July 1980 BSI 04-2000 First published March 1974 First revision July 1980 The following BSI references relate to the work on this standard: Committee reference PVC/1 Draft for approval 80/50490 ISBN 0 580 11541 0 Amendments issued since publication Amd. No.Dat
4、e of issueComments 8682December 1995 Indicated by a sideline in the margin Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:56:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 787-23:1995 BSI 04-2000i Contents Page National forewordii Foreword2 Text of EN ISO 787-233 Publications ref
5、erred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:56:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 787-23:1995 ii BSI 04-2000 National foreword This revision of Part B9 of BS 3483 has been prepared under the direction of the Pigments, Paints and Varnishes
6、Standards Committee. It is identical with ISO 787-23 “General methods of test for pigments and extenders Part 23: Determination of density (using a centrifuge to remove entrained air)” published in 1979 by the International Organization for Standardization (ISO). The 1974 edition of Part B9 is now w
7、ithdrawn. In 1995 the European Committee for Standardization (CEN) accepted ISO 787-23:1979 as European Standard EN ISO 787-23:1995. As a consequence of implementing the European Standard this British Standard is renumbered as BS EN ISO 787-23 and any reference to BS 3483-B9 should be read as a refe
8、rence to BS EN ISO 787-23. Terminology and conventions. The text of the International Standard has been approved as suitable for publication, without deviation, as a British Standard. Some terminology and certain conventions are not identical with those used in British Standards; attention is especi
9、ally drawn to the following. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the base line as the decimal marker. In 1.1 and 1.2 “Part 23 of this International Standard” and “Part 10 of this International Standard” should be read as “Pa
10、rt B9 of this British Standard” and “Part B8 of this British Standard” respectively. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of its
11、elf confer immunity from legal obligations. Cross-references International StandardCorresponding British Standard ISO 787-10aBS 3483 Methods for testing pigments for paints Part B8:1974 Determination of density relative to water at 4 C (using a vacuum to remove entrained air) (Technically equivalent
12、) ISO 842:1974BS 4726:1971 Methods for sampling raw materials for paints and varnishes (Technically equivalent) a Revision of ISO/R 787-10 in course of preparation. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN ISO title page, pages 2 to 4, an
13、inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:56:51 GMT+00:00 2006, Uncontrolled Copy
14、, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 787-23 August 1995 ICS 87.060.10; 87.060.30 Descriptors: Paints, pigments, tests, density measurement English version General methods of tests for pigments and extenders Part 23: Determination of density (using a centrifuge to remove
15、 entrained air) (ISO 787-23:1979) Mthodes gnrales dessai des pigments et matires de charge Partie 23: Dtermination de la masse volumique (en utilisant une centrifugeuse pour chasser lair entrain) (ISO 787-23:1979) Allgemeine Prverfahren fr Pigments und Fllstoffe Teil 23: Bestimmung der Dichte (unter
16、 Verwendung einer Zentrifuge zum Entfernen eingeschlossener Luft) (ISO 787-23:1979) This European Standard was approved by CEN on 1995-03-23. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a nat
17、ional standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in a
18、ny other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ice
19、land, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1995 All rights of reprodu
20、ction and communications in any form and by any means reserved in all countries to CEN and its members. Ref. No. EN ISO 787-23:1995 E Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:56:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 787-23:1995 BSI 04-2000 2 Foreword The text of the I
21、nternational Standard from ISO/TC 35, Paints and varnishes, of the International Organization for Standardization (ISO) has been taken over as a European Standard by the Technical Committee CEN/TC 298, Pigments and extenders. This European Standard shall be given the status of a National Standard, e
22、ither by publication of an identical text or by endorsement, at the latest by February 1996, and conflicting national standards shall be withdrawn at the latest by February 1996. According to CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Aus
23、tria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Contents Page Foreword2 0Introduction3 1Scope and field of application3 2References3 3Preliminary considerations3 4Apparatus3 5
24、Sampling3 6Procedure3 7Expression of results4 8Precision4 9Test report4 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:56:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 787-23:1995 BSI 04-20003 0 Introduction This document is a part of ISO 787, General methods of test for pigments a
25、nd extenders. 1 Scope and field of application 1.1 Part 23 of this International Standard specifies a general method of test for determining the density of a sample of pigment or extender, using a centrifuge to remove entrained air. NOTEWhen this general method is applicable to a given pigment or ex
26、tender, only a cross-reference to it should be included in the International Standard relating to that pigment or extender, with a note of any detailed modification which may be needed in view of the special properties of the material in question. Only when this general method is not applicable to a
27、 particular material should a special method for determination of density using a centrifuge be specified. 1.2 Part 10 of this International Standard specifies a general method of test for determining the density of a sample of pigment or extender, using a pyknometer. 2 References ISO 787, General m
28、ethods for pigments and extenders Part 10: Determination of density Pyknometer method1). ISO 842, Raw materials for paints and varnishes Sampling. 3 Preliminary considerations 3.1 Displacement liquids of known density A liquid should be selected in which the material to be tested is insoluble, and w
29、hich has good wetting properties and a low evaporation rate under vacuum. High-boiling aromatic or aliphatic hydrocarbon solvents with a boiling point over 170 C are suitable. Particular care, however, may be necessary in the selection of the liquid if carbon black or organic dyestuffs are to be exa
30、mined. 3.2 Temperature of the determination The temperature t at which the determination is carried out will significantly affect the density of the displacement liquid used, but not that of the material tested. When using this method, therefore, it is most important that each weighing should be mad
31、e at a constant temperature. It is desirable that a constant temperature room or enclosure should be used but if these are not available the temperature at which each weighing is made should be noted and corrections made to the density of the displacement liquid. 4 Apparatus 4.1 Centrifuge tube of g
32、lass or other suitable material such as polypropylene or stainless steel. 4.2 Cradle and loop of fine platinum or nickel-chromium wire not more than 0,12 mm diameter to suspend the tube from the balance. 4.3 Glass stirring rod, slightly longer than the tube (4.1). 4.4 Centrifuge, laboratory type. 4.
33、5 Sieve, with nominal mesh aperture of 500 4m. 4.6 Balance, accurate to 1 mg or better. 5 Sampling Take a representative sample of the material to be tested as described in ISO 842. 6 Procedure 6.1 Test portion Thoroughly mix a sufficient quantity of the test sample to occupy about half the volume o
34、f the centrifuge tube (4.1), and pass it through the sieve (4.5). Dry by heating it at 105 2 C for 2 h and allow to cool to room temperature in a desiccator. 6.2 Determination Clean and thoroughly dry the tube and stirring rod (4.3). Suspend them from the balance (4.6) by means of the cradle and loo
35、p (4.2) and weigh them in air. Completely immerse the tube and stirring rod in the displacement liquid contained in a 250 ml beaker, and allow to stand for a sufficient time in the constant-temperature room or enclosure for the whole to reach the temperature of the room or enclosure (the time necess
36、ary for this may be 1 h or longer). Suspend the tube and stirring rod from the balance and weigh. Remove the tube and stirring rod from the displacement liquid and wipe them clean and dry. Weigh into the tube a quantity of the dried sample sufficient to occupy about half the volume (the quantity req
37、uired for this is from 1 to 10 g depending on the density). Add displacement liquid to the material in the tube, gradually and with careful stirring, until the material is wetted and completely covered and has a layer of clear liquid above it. Add further displacement liquid to bring the level to ab
38、out 13 mm from the top of the tube. 1) At present at the stage of draft. (Revision of ISO/R 787-10:1970.) Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:56:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 787-23:1995 4 BSI 04-2000 Place the tube, complete with stirring rod, into the c
39、entrifuge (4.4), suitably balanced, and spin it until the occluded air is removed and the solid material is reduced to a closely packed mass (for a centrifuge operating at 4 500 r/min a period of 15 min should be sufficient). Remove the tube from the centrifuge and fill it with displacement liquid.
40、Lower the tube and stirring rod carefully into a 250 ml beaker containing displacement liquid, and allow the whole to stand in the constant-temperature room or enclosure until the temperature of the whole is at the temperature of the room or enclosure. Suspend the tube and stirring rod by means of t
41、he cradle and loop and weigh. 7 Expression of results Calculate the density of the material tested, expressed in grams per millilitre, by the formula where m1is the mass, in grams, of the cradle (4.2), tube (4.1) and stirring rod (4.3) in the displacement liquid; m2is the mass, in grams, of the mate
42、rial in air; m3is the mass, in grams, of the cradle, tube, stirring rod and material in the displacement liquid; is the density, in grams per millilitre, of the displacement liquid at the temperature t. 8 Precision 8.1 Repeatability (r) The value below which the absolute difference between two singl
43、e test results on identical material, obtained by one operator in one laboratory using the same equipment within a short interval of time using the standard test method, may be expected to lie with a 95 % probability, is 0,03 g/ml. 8.2 Reproducibility (R) The value below which the absolute differenc
44、e between two test results, each the mean of duplicate measurements, on identical material, obtained by operators in different laboratories, using the standardized test method, may be expected to lie with a 95 % probability, is 0,05 g/ml. 9 Test report The test report shall include at least the foll
45、owing information: a) the type and identification of the product tested; b) a reference to this International Standard or to a corresponding national standard; c) details of the displacement liquid used and the temperature of the determination; d) any deviation, by agreement or otherwise, from the t
46、est procedure specified; e) the result of the test; f) the date of test. m2 m2(m3m1) - - Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:56:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 787-23:1995 BSI 04-2000 Publications referred to See national foreword. Licensed Copy: sheffie
47、ldun sheffieldun, na, Mon Nov 20 02:56:51 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 787-23:1995 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards
48、 in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of o
49、ur products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: 020 8996 9000. Fax: 020 8996 7400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards. Buying standards Orders for all BSI, international an
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