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、80BSENISO787-23:1995 This British Standard, having been prepared under the directionof the Pigments, Paintsand Varnishes StandardsCommittee, was published underthe authority ofthe Executive Board and comesinto effect on 31 July 1980 BSI 04-2000 First published March 1974 First revision July 1980 The
3、 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. Date of issue Comments 8682 December 1995 Indicated by a sideline in the marginBSENISO787-23:1995 BSI 04-2000 i Content
4、s Page National foreword ii Foreword 2 Text of EN ISO 787-23 3 Publications referred to Inside back coverBSENISO787-23:1995 ii BSI 04-2000 National foreword This revision of Part B9 of BS 3483 has been prepared under the direction of thePigments, Paints and Varnishes Standards Committee. It is ident
5、ical withISO787-23 “General methods of test for pigments and extenders Part23: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 The 1974 edition of Part B9 is now withdrawn. In 1995 the European Commi
6、ttee 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 reference to BS EN ISO 787-23. Terminolo
7、gy 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 especially drawn to the following. The com
8、ma 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 “Part B9 of this British Standard” and
9、“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 itself confer immunity from legal oblig
10、ations. Cross-references International Standard Corresponding British Standard ISO 787-10 a BS 3483 Methods for testing pigments for paints Part B8:1974 Determination of density relative to waterat 4 C (using a vacuum to remove entrained air) (Technically equivalent) ISO 842:1974 BS 4726:1971 Method
11、s 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, pagesi andii, theEN ISO title page, pages2 to4, an inside back cover and a back cover. Th
12、is 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.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 787-23 August 1995 ICS 87.060.10; 87.060.30 Descriptors: Paints, pigments, test
13、s, density measurement English version General methods of tests for pigments and extenders Part23: Determination of density (using a centrifuge toremove entrained air) (ISO 787-23:1979) Mthodes gnrales dessai des pigments et matires de charge Partie 23: Dtermination de la masse volumique (en utilisa
14、nt une centrifugeuse pour chasser lair entrain) (ISO787-23:1979) Allgemeine Prverfahren fr Pigments und Fllstoffe Teil 23: Bestimmung der Dichte (unter Verwendung einer Zentrifuge zum Entfernen eingeschlossener Luft) (ISO 787-23:1979) This European Standard was approved by CEN on 1995-03-23. CEN mem
15、bers are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on applicat
16、ion to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the
17、same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardiz
18、ation Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1995 All rights of reproduction 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 EENISO787-23:1995
19、 BSI 04-2000 2 Foreword The text of the International 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 g
20、iven the status of a National Standard, either 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
21、 to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. Contents Page Foreword 2 0 Introduction 3 1 Scope and field of application 3 2 Referenc
22、es 3 3 Preliminary considerations 3 4 Apparatus 3 5 Sampling 3 6 Procedure 3 7 Expression of results 4 8 Precision 4 9 Test report 4ENISO787-23:1995 BSI 04-2000 3 0 Introduction This document is a part of ISO 787, General methods of test for pigments and extenders. 1 Scope and field of application 1
23、.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 extender, only a cross-reference to it should be i
24、ncluded 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 particular material should a special method for
25、 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 methods for pigments and extenders Part 10: Deter
26、mination of density Pyknometer method 1) . 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 which has good wetting properties and a low eva
27、poration rate under vacuum. High-boiling aromatic or aliphatic hydrocarbon solvents with a boiling point over170 C are suitable. Particular care, however, may be necessary in the selection of the liquid if carbon black or organic dyestuffs are to be examined. 3.2 Temperature of the determination The
28、 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 made at a constant temperature. It is desirable th
29、at 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 glass or other suitable material such as polypro
30、pylene or stainless steel. 4.2 Cradle and loop of fine platinum or nickel-chromium wire not more than 0,12mm 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. 4.5 Sieve, with nominal mesh aperture of 5004m. 4.6
31、 Balance, accurate to 1 mg or better. 5 Sampling Take a representative sample of the material to be tested as described in ISO842. 6 Procedure 6.1 Test portion Thoroughly mix a sufficient quantity of the test sample to occupy about half the volume of the centrifuge tube (4.1), and pass it through th
32、e 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 loop (4.2) and weigh them in air. Completely immerse the
33、 tube and stirring rod in the displacement liquid contained in a250 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 necessary for this may be1h or longer). Suspend the tube and
34、 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 required for this is from1 to10g depending on the density).
35、 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 about 13mm from the top of the tube. 1) At present at the sta
36、ge of draft. (Revision of ISO/R 787-10:1970.)ENISO787-23:1995 4 BSI 04-2000 Place the tube, complete with stirring rod, into the centrifuge (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 a
37、t4500r/min a period of15min should be sufficient). Remove the tube from the centrifuge and fill it with displacement liquid. Lower the tube and stirring rod carefully into a250ml beaker containing displacement liquid, and allow the whole to stand in the constant-temperature room or enclosure until t
38、he temperature of the whole is at the temperature of the room or enclosure. Suspend the tube and stirring rod by means of the 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 m 1 is the mass, in g
39、rams, of the cradle (4.2), tube (4.1) and stirring rod (4.3) in the displacement liquid; m 2 is the mass, in grams, of the material in air; m 3 is 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 displaceme
40、nt liquid at the temperature t. 8 Precision 8.1 Repeatability (r) The value below which the absolute difference between two single 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, m
41、ay be expected to lie with a95% probability, is 0,03g/ml. 8.2 Reproducibility (R) The value below which the absolute difference between two test results, each the mean of duplicate measurements, on identical material, obtained by operators in different laboratories, using the standardized test metho
42、d, may be expected to lie with a95% probability, is 0,05g/ml. 9 Test report The test report shall include at least the following 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
43、 displacement liquid used and the temperature of the determination; d) any deviation, by agreement or otherwise, from the test procedure specified; e) the result of the test; f) the date of test. m 2 m 2 (m 3 m 1 ) -BSENISO787-23:1995 BSI 04-2000 Publications referred to See national foreword.BS EN
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