1、BRITISH STANDARD BS EN ISO 787-9:1995 Incorporating Amendment No. 1 General methods of test for pigments and extenders Part 9: Determination of pH value of aqueous suspension The European Standard EN ISO 787-9:1995 has the status of a British StandardBSENISO787-9:1995 This British Standard, having b
2、een prepared under the directionof the Pigments, Paintsand Varnishes StandardsCommittee, was published under the authority ofthe Board of BSI and comesintoeffect on 30November1982 BSI 04-2000 First published March 1974 First revision November 1982 The following BSI references relate to the work on t
3、his standard: Committee reference PVC/1 Draft for comment 80/50282 DC ISBN 0 580 12941 1 Amendments issued since publication Amd. No. Date of issue Comments 8512 August 1995 Indicated by a sideline in the marginBSENISO787-9:1995 BSI 04-2000 i Contents Page National foreword ii Foreword 2 Text of EN
4、ISO 787-9 3 Publication referred to Inside back coverBSENISO787-9:1995 ii BSI 04-2000 National foreword This revision of Part C4 of BS 3483 has been prepared under the direction of thePigments, Paints and Varnishes Standards Committee. It is identical withISO 787-9 “General methods of test for pigme
5、nts and extenders Part9:Determination of pH value of an aqueous suspension” published in 1981 bythe International Organization for Standardization (ISO). In 1994 the European Committee for Standardization (CEN) accepted ISO 787-9:1981 as European Standard EN ISO 787-9:1995. As a consequence ofimplem
6、enting the European Standard this British Standard is renumbered as BS EN ISO 787-9 and any reference to BS 3483-C4 should be read as a reference to BS EN ISO 787-9. This Part of BS 3483 supersedes BS 3483-C4:1974 which is withdrawn. Terminology and conventions. The text of the International Standar
7、d has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is especially drawn to the following. The comma has been used throughout as a decimal marker. In British
8、 Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever the words “This part of ISO 787” and “International Standard” appear, referring to this standard, they should be read as “This Part of BS 3483” and “British Standard” respectively. Additional inform
9、ation. In the last paragraph of clause 6 of ISO 787-9:1981, it is stated that the procedure is to be repeated if the duplicate determinations differ by more than 0,3 unit. In implementing this standard in the United Kingdom, it is recommended that, if repeat determinations are necessary, wherever po
10、ssible both the sampling (clause 5) and the procedure (clause 6) should be repeated. In paragraph 1 of clause 6, the room temperature is unspecified. It is recommended that the temperature of the test should be 23 2 C. 1) A British Standard does not purport to include all the necessary provisions of
11、 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 obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN ISO title page, page
12、s2 to4, an 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. Cross-reference International Standard Corresponding British Standard ISO 842:1974 BS
13、4726:1971 Methods for sampling raw materials for paints and varnishes (Technically equivalent) 1) These changes have been reported to the ISO in a proposal to amend the text of the International Standard.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 787-9 March 1995 ICS 87.060.10 Descript
14、ors: Paints, pigments, tests, chemical analysis, determination of content, pH English version General methods of test for pigments and extenders Part9: Determination of pH value of aqueous suspension (ISO 787-9:1981) Mthodes gnrales dessai des pigments et matires de charge Partie 9: Dtermination du
15、pH dune suspension aqueuse (ISO 787-9:1981) Allgemeine Prfverfahren fr Pigmente und Fllstoffe Teil 9: Bestimmung des pH-Wertes einer wrigen Suspension (ISO 787-9:1981) This European Standard was approved by CEN on 1994-10-17. CEN members are bound to comply with the CEN/CENELEC Internal Regulations
16、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 application to the Central Secretariat or to any CEN member. This European
17、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 same status as the official versions. CEN members are the national
18、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 Standardization Comit Europen de Normalisation Europisches Komitee fr Normung
19、 Central Secretariat: rue de Stassart 36, B-1050 Brussels 1995 All rights of reproduction and communication in any form and by any means reserved in all countries to CEN and its members Ref. No. EN ISO 787-9:1995 EENISO787-9:1995 BSI 04-2000 2 Foreword This European Standard has been taken over by t
20、he Technical Committee CEN/TC 298, Pigments and extenders, from the work of ISO/TC 35, Paints and varnishes, of the International Organization for Standardization (ISO). This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsem
21、ent, at the latest by September 1995, and conflicting national standards shall be withdrawn at the latest by September 1995. According to the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany,
22、Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Contents Page Foreword 2 0 Introduction 3 1 Scope and field of application 3 2 Reference 3 3 Reagent 3 4 Apparatus 3 5 Sampling 3 6 Procedure 3 7 Expression of results 3 8 Test
23、report 4ENISO787-9:1995 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 This part of ISO 787 specifies a general method of test for determining the pH value of an aqueous suspension of a sample of p
24、igment or extender. NOTEWhen this general method is applicable to a given pigment or extender, 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 prope
25、rties of the material in question. Only when this general method is not applicable to a particular material should a special method for determination of pH value be specified. 2 Reference ISO 842, Raw materials for paints and varnishes Sampling. 3 Reagent Freshly distilled water, boiled before use t
26、o remove carbon dioxide, or water otherwise prepared of at least equivalent purity. The water shall be boiled and cooled in a vessel made of chemically resistant glass, immediately before use. It shall be boiled for5 to 10 min only, in order to avoid an increase of its pH value due to alkali dissolv
27、ed from the glass vessel. Because water rapidly absorbs carbon dioxide, the cooled water shall be protected from access to the atmosphere and shall be stored for not more than30min. The closed container should be protected by a soda asbestos tube or similar device. 4 Apparatus 4.1 Glass container, o
28、f capacity 50 ml, made of chemically resistant glass, fitted with a ground glass or rubber stopper. Before using the container for the first time, boil dilute hydrochloric acid placed in the container and then rinse it thoroughly with distilled water. The rubber stopper shall not have been used for
29、any other purpose. 4.2 pH measuring device, capable of measurement to 0,1 unit, calibrated against buffer solutions of known pH value at the temperature of the test. 4.3 Balance, with an appropriate accuracy. 5 Sampling Take a representative sample of the material to be tested as described in ISO 84
30、2. 6 Procedure 2) Carry out the determination in duplicate at room temperature. Prepare a 10% (m/m) suspension of the material under test, using the distilled water (clause 3), in the glass container (4.1). Stopper the container andshake it vigorously for 1 min. Allow it to stand for 5 min, remove t
31、he stopper and determine, to the nearest 0,1 unit, the pH value of the suspension. If the material does not disperse easily in water, a wetting agent should be used; in the case of materials not soluble in ethanol, up to 5ml of ethanol may be used but care should be taken to ensure that the minimum
32、quantity is used and that it is neutral and free from pyridine. In the case of pigments soluble in ethanol, a neutral non-ionic wetting agent such as 10ml of a 0,01% (m/m) solution of an ethylene oxide condensate should be used. The neutrality of the wetting agent should be checked by making a blank
33、 determination. If a wetting agent is used, the volume of the water should be reduced so that a10% (m/m) suspension is obtained. The type and quantity of wetting agent used shall be stated in the test report. NOTEWith pigments and extenders of relatively low density, it may be necessary to use a sus
34、pension of less than 10% (m/m). In such cases the concentration of the suspension used should be stated in the test report. Record the pH values to the nearest 0,1 unit and record the temperature 2)of the suspension to the nearest1 C. If the duplicate determinations of pH differ by more than 0,3 uni
35、t, the procedure shall be repeated. 7 Expression of results Calculate the mean of two determinations and report the result to the nearest 0,1 unit. 2) See the paragraphs headed “Additional information” in the national foreword.ENISO787-9:1995 4 BSI 04-2000 8 Test report The test report shall contain
36、 at least the following information: a) the type and identification of the product tested; b) a reference to this International Standard (ISO787-9); c) if used, the type and quantity of wetting agent; d) the result of the test as indicated in clause 7, and the test temperature; e) any deviation, by
37、agreement or otherwise, from the procedure specified; f) the date of the test.BSENISO787-9:1995 BSI 04-2000 Publication referred to See the national foreword.BS EN ISO 787-9:1995 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible
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