EN 15802-2009 en Conservation of cultural property - Test methods - Determination of static contact angle《文化遗产保护的试验方法 静态接触角的测定》.pdf

1、BS EN 15802:2009ICS 97.195NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDConservation ofcultural property Test methods Determination of staticcontact angleThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 J

2、anuary2010 BSI 2010ISBN 978 0 580 61876 5Amendments/corrigenda issued since publicationDate CommentsBS EN 15802:2009National forewordThis British Standard is the UK implementation of EN 15802:2009.The UK participation in its preparation was entrusted to TechnicalCommittee B/560, Conservation of tang

3、ible cultural heritage.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot

4、confer immunityfrom legal obligations.BS EN 15802:2009EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15802 December 2009 ICS 97.195 English Version Conservation of cultural property - Test methods - Determination of static contact angle Conservation des biens culturels - Mthodes dessai - Dterm

5、ination de langle de contact statique Erhaltung des kulturellen Erbes - Prfverfahren - Messung des statischen Kontaktwinkels This European Standard was approved by CEN on 7 November 2009. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giv

6、ing 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 CEN Management Centre or to any CEN member. This European Standard exists in three official ve

7、rsions (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 CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgi

8、um, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR

9、STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15802:2009: EBS EN 15802:2009EN 15802:2009 (E)

10、2 Contents Page Foreword 3Introduction .41 Scope 52 Normative references 53 Terms and definitions .54 Principle 56 Test equipment 67 Preparation of test specimens .77.1 Number and dimensions of test specimens .77.2 Pre-conditioning of test specimens .78 Test procedure .79 Expression of results 89.1

11、Calculation of the static contact angle 810 Test report 8Annex A (informative) Physical meaning of the static contact angle . 10Bibliography . 11BS EN 15802:2009EN 15802:2009 (E) 3 Foreword This document (EN 15802:2009) has been prepared by Technical Committee CEN/TC 346 “Conservation of cultural pr

12、operty”, the secretariat of which is held by UNI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2010 and conflicting national standards shall be withdrawn at the latest by June 2010. Attent

13、ion is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of t

14、he following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovak

15、ia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. BS EN 15802:2009EN 15802:2009 (E) 4 Introduction This test method can be applied if it does not change the value of the cultural property and follows relevant ethical codes of conservation practice. BS EN 15802:2009EN 15802:2009 (E) 5 1 Sc

16、ope This European Standard specifies a method for the measurement of the static contact angle of a water drop on porous inorganic materials used for and constituting cultural property. The method may be applied to porous inorganic materials either untreated or subjected to any treatment or ageing. 2

17、 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. prEN 15898:2009, Conservati

18、on of cultural property Main general terms and definitions concerning conservation of cultural property 3 Terms and definitions For the purposes of this document, the terms and definitions given in prEN 15898:2009 and the following apply. 3.1 porous inorganic materials materials including natural st

19、ones, e.g. sandstone, limestone, marble, as well as artificial materials, such as mortar, plaster, brick and others 3.2 static contact angle angle , in degrees, formed by the surface of the specimen and the tangent to the water drop at the contact point, as shown in Figure 1 Key d diameter of the co

20、ntact surface, in mm h height, in mm static contact angle, in degrees Figure 1 Static contact angle at time t 4 Principle Determination of the static contact angle between a water drop and the test surface of the specimen. BS EN 15802:2009EN 15802:2009 (E) 6 5 Symbols and abbreviations For the purpo

21、ses of this document, the following symbols and abbreviations apply: d diameter of the contact surface, in mm h height, in mm static contact angle, in degrees 6 Test equipment 6.1 Test equipment for the measurement of static contact angle consists of: i) an illumination source (1) that will not affe

22、ct the temperature of the drop/specimen system, ii) a flat sample holder (2), iii) a drop deposition system, usually consisting of a graduated micro-pipette (3), with a flat head needle, positioned above and perpendicular to the specimen surface and able to deliver reproducible drops, iv) an optical

23、 system (4) that projects the image of the deposited water drop onto a screen (5) on which the height of the water drop and the diameter of the contact surface can be marked with a ruler (6). This part of the instrument can consist of a camera (4) able to record the image on a screen (5) where the p

24、arameters can be measured manually or automatically. The measurement principle of most commercial instruments available on the market is shown in Figure 2. Key 1 illumination source 2 sample holder 3 graduated micro-pipette 4 optical system 5 screen 6 ruler Figure 2 Schematic sketch of the measureme

25、nt system BS EN 15802:2009EN 15802:2009 (E) 7 6.2 Sand paper with grain size of 82 m (corresponding to grit number P180 according to the FEPA1)classification). 6.3 A soft brush. 6.4 Desiccator filled with desiccant such as indicating silica gel or other drying agents. 6.5 A ventilated oven which can

26、 maintain a temperature of (60 2) C. 6.6 An analytical balance with an accuracy of 0,1 mg for sample less than 200g and accuracy of 1 mg for samples more than 200 g. 6.7 A chronometer with an accuracy of 1 s. 6.8 Deionised or distilled water (with max. conductivity of 6 S). 7 Preparation of test spe

27、cimens 7.1 Number and dimensions of test specimens The shape and dimensions of the specimens shall be conformed to the requirements of the chosen test equipment (usually 10 mm to 20 mm of thickness). The test surface shall be flat. Specimens that do not have parallel surfaces can only be tested usin

28、g apparatus that adjusts for this. The number and dimensions of specimens are dependent on the heterogeneity of the material. Each series shall consist of at least 3 specimens. All dimensions shall have a 0,5 mm tolerance. 7.2 Pre-conditioning of test specimens The surface chosen for the determinati

29、on of static contact angle shall be flat and wet or dry polished with sand paper (6.2). After polishing, the specimens shall be washed with water, gently brushed with a soft brush and immersed in deionised water for 30 min. In case of water-sensitive materials, for example gypsum containing material

30、s, only dry polishing and compressed air shall be used. After smoothing and washing, the surface should not to be touched with hands. The above procedure does not necessary apply to treated specimens or specimens taken from exposed surfaces. Test specimens shall be dried to constant mass in a ventil

31、ated oven at a temperature of (60 2) C until a constant weight is reached, and stored in a desiccator until the test starts. If the material is temperature-sensitive, the pre-conditioning shall be conducted in a desiccator filled with desiccant or in a ventilated oven at a temperature of (40 2) C ti

32、ll constant mass is reached. Constant mass is reached when the difference between two successive weighings at an interval of 24 h is not greater than 0,1% of the mass of the specimen. 8 Test procedure Fill the micro-pipette with deionised/distilled water taking care that the needle is clean, outside

33、 and inside, to prevent air bubbles or drop deformation. The specimen is mounted on the sample holder in such a way that the test surface is horizontal. 1) FEPA Federation of European Producers of Abrasives BS EN 15802:2009EN 15802:2009 (E) 8 Build up a drop with a volume in the range between 5 l an

34、d 10 l. Deposit the drop on the specimen surface by slowly lowering the micro-pipette and by taking care that the drop is detaching. The measurement of d, h and (see Figure 1) shall be carried out 10 s after the deposition of the drop. In case of macroscopically asymmetric drops, measurements shall

35、be repeated. If the drop loses at least 50 % of its volume in the first 10 s measurement is not possible and this shall be noted in the test report. For each representative specimen for which the material and treatment are the same, the number of measurements shall be at least 15, including cases of

36、 fast absorption. Drops shall be deposited at a distance of at least 3 mm from each other to avoid overlapping. 9 Expression of results 9.1 Calculation of the static contact angle Assuming a spherical drop, the contact angle is calculated according to the following equation: dharctg22= where d is th

37、e diameter of the contact surface, in mm; h is the height, in mm; is the static contact angle, in degrees. If a different algorithm or method is used, it shall be reported in the test report. 10 Test report The test report shall contain the following information: a) reference to this European Standa

38、rd; b) name and address of the test laboratory in which the test was carried out; c) date of testing (yy-mm-dd); d) type, name, provenance, description of the porous inorganic material including chemical, petrographical, mineralogical and physical characteristics (if available) in accordance with ex

39、isting standards; e) number, shape, dimensions of the specimens and orientation of anisotropy present, if any; f) description of pre-conditioning; g) description of the test surface of the specimens, the date when the specimens were prepared, type and date of the treatment applied, if any; h) type o

40、f instrument; i) type of micro-pipette (material and volume of micro drop); j) measuring methodology, if different from the one described in Clause 8; BS EN 15802:2009EN 15802:2009 (E) 9 k) number of measurements for each sample; l) contact angle of single measurements; m) mean value of the measurem

41、ents obtained on one specimen and the mean of the set of specimens; n) standard deviation; o) number of events, such as drop absorption, for which a correct measurement of the drop was not possible; p) all deviations from this European Standard and their justification; q) any additional remarks. BS

42、EN 15802:2009EN 15802:2009 (E) 10 Annex A (informative) Physical meaning of the static contact angle The contact angle of a liquid on a surface is widely used to predict wetting and adhesion properties of the solid by calculating its solid-vapour surface tension. The contact angle of a liquid on a s

43、urface is frequently used to estimate the wetting properties of the solid by calculating its surface tension. Its definition is based on the equilibrium of a drop on an ideal (i.e. flat, horizontal, smooth, homogeneous, isotropic and rigid) surface, according to the Young relationship: where SVis th

44、e solid-vapour interfacial tension, SLis the solid-liquid interfacial tension and LVis the liquid surface tension. Looking at a cross-section of a drop on a solid, is the inclusive angle between the direction of SLand the direction of LV, tangent to the external surface of the drop, with the vertex

45、at the three-phase liquid-solid-vapour intersection. Looking at a cross-section of a drop on a solid, is the inclusive angle between vector SLand vector LV, tangent to the external surface of the drop and having its vertex at the intersection of the three-phase system. Under these hypotheses, a cont

46、act angle corresponds to the thermodynamic value that minimizes the surface free energy. Figure A.1 Cross-section of static contact angle Instead, on a real surface it is generally found that a range of contact angles is possible experimentally causing wetting or contact angle hysteresis. The reason

47、 is that contact angle phenomena are very complicated. Contact angles on “non-ideal” surfaces are not only influenced by the interfacial tensions according to Young relationship, but also by many other phenomena, such as surface roughness, chemical heterogeneity, sorption layers, molecular orientati

48、on, swelling and partial solution of the constituents in the material. These effects have to be considered and the initial hypothesis of “ideal surface” is no longer valid. The contact angle value, where the system assumes its absolute minimum of surface free energy, is called equilibrium contact an

49、gle, while the other possible contact angles correspond to different metastable equilibrium states depending on the surface and on different initial conditions. The highest value in this range is commonly defined as advancing contact angle, while the lowest is defined as contact angle. The advancing angle refers to a wetting process, where liquid is changing, or has changed, a dry solid surface into a wet one. The word “advancing“ comes from the requirement that the drop is just ready to spread