SANS 8502-5-2008 Preparation of steel substrates before application of paints and related products - Tests for the assessment of surface cleanliness Part 5 Measurement of chloride det.pdf

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1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21221-6 SANS 8502-5:2008Edition 1ISO 8502-5:1998Edition 1SOUTH AFRICAN NATIONAL STANDARD Preparation of steel substrates before applicatio

4、n of paints and related products Tests for the assessment of surface cleanliness Part 5: Measurement of chloride on steel surfaces prepared for painting (ion detection tube method) This national standard is the identical implementation of ISO 8502-5:1998 and is adopted with the permission of the Int

5、ernational Organization for Standardization. Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa SANS 8502-5:2008 Edition 1 ISO 8502-5:1998 Edition 1 Tab

6、le of changes Change No. Date Scope National foreword This South African standard was approved by National Committee StanSA SC 5140.11D, Paints and varnishes Industrial coatings, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This docume

7、nt was published in April 2008. AReference numberISO 8502-5:1998(E)INTERNATIONALSTANDARDISO8502-5First edition1998-02-15Preparation of steel substrates beforeapplication of paints and relatedproducts Tests for the assessment ofsurface cleanliness Part 5:Measurement of chloride on steel surfacesprepa

8、red for painting (ion detection tubemethod)Prparation des subjectiles dacier avant application de peintures et deproduits assimils Essais pour apprcier la propret dune surface Partie 5: Mesurage des chlorures sur les surfaces dacier prpares pour lamise en peinture (mthode du tube dtecteur dions)SANS

9、 8502-5:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 8502-5:1998(E) ISO 1998All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by anymeans, electronic or mechan

10、ical, including photocopying and microfilm, without permission in writing from the publisher.International Organization for StandardizationCase postale 56 CH-1211 Genve 20 SwitzerlandInternet centraliso.chX.400 c=ch; a=400net; p=iso; o=isocs; s=centralPrinted in SwitzerlandiiForewordISO (the Interna

11、tional Organization for Standardization) is a worldwide federation of nationalstandards bodies (ISO member bodies). The work of preparing International Standards isnormally carried out through ISO technical committees. Each member body interested in asubject for which a technical committee has been

12、established has the right to be representedon that committee. International organizations, governmental and non-governmental, inliaison with ISO, also take part in the work. ISO collaborates closely with the InternationalElectrotechnical Commission (IEC) on all matters of electrotechnical standardiz

13、ation.Draft International Standards adopted by the technical committees are circulated to themember bodies for voting. Publication as an International Standard requires approval by atleast 75 % of the member bodies casting a vote.International Standard ISO 8502-5 was prepared by Technical Committee

14、ISO/TC 35, Paintsand varnishes, Subcommittee SC 12, Preparation of steel substrates before application ofpaints and related products.ISO 8502 consists of the following parts, under the general title Preparation of steelsubstrates before application of paints and related products Tests for the assess

15、ment ofsurface cleanliness: Part 1: Field test for soluble iron corrosion products Technical Report Part 2: Laboratory determination of chloride on cleaned surfaces Part 3: Assessment of dust on steel surfaces prepared for painting (pressure-sensitive tape method) Part 4: Guidance on the estimation

16、of the probability of condensation prior to paint application Part 5: Measurement of chloride on steel surfaces prepared for painting (ion detection tube method) Part 6: Extraction of soluble contaminants for analysis The Bresle method Part 8: Field method for refractometric determination of moistur

17、e Part 9: Field method for the conductometric determination of water-soluble salts. Part 10: Field method for the titrimetric determination of chlorideFurther parts are planned.SANS 8502-5:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .I

18、NTERNATIONAL STANDARD ISO ISO 8502-5:1998(E)1Preparation of steel substrates before application of paints andrelated products Tests for the assessment of surface cleanliness Part 5:Measurement of chloride on steel surfaces prepared for painting(ion detection tube method)1 ScopeThis part of ISO 8502

19、describes a field test for the measurement of chloride ions using specialdetection tubes.With suitable surface sampling techniques, the test is applicable to steel surfaces before and aftercleaning, as well as to painted surfaces between applications of coats.NOTE ISO 8502-2, Preparation of steel su

20、bstrates before application of paints andrelated products Tests for the assessment of surface cleanliness Part 2: Laboratorydetermination of chloride on cleaned surfaces, describes a laboratory method for thedetermination of chloride on a surface.2 Normative referenceThe following standard contains

21、provisions which, through reference in this text, constituteprovisions of this part of ISO 8502. At the time of publication, the edition indicated was valid.All standards are subject to revision, and parties to agreements based on this part of ISO 8502 areencouraged to investigate the possibility of

22、 applying the most recent edition of the standardindicated below. Members of IEC and ISO maintain registers of currently valid InternationalStandards.ISO 3696:1987, Water for analytical laboratory use Specification and test methods.3 PrincipleA proportion of the water-soluble chlorides on the test s

23、ubstrate is removed by controlledwashing or immersion in water. The collected washings are analysed to determine the chlorideion concentration, which is indicated by a colour change in a detection tube containing silverchromate.SANS 8502-5:2008This s tandard may only be used and printed by approved

24、subscription and freemailing clients of the SABS .ISO 8502-5:1998(E) ISO24 Apparatus and materials4.1 Water, of at least grade 3 purity in accordance with ISO 3696.4.2 Chloride ion detection tube4.2.1 DesignThe detection tube shall comprise a borosilicate glass tube, 140 mm to 150 mm in length and2

25、mm to 3 mm inside diameter, containing 5 % (m/m) analytical reagent grade silver chromatein a silica sand carrier. The silica sand shall have a particle size range from 177 m to250 m. The mixture of sand and chromate shall be retained in the tube by plugs of cottonwool in both ends and glass powder

26、control material between the carrier and the plugs. Bothends of the glass tube shall be sealed by fusing the glass.NOTE If the tube is properly designed, the cotton wool will not be burnt.4.2.1 CalibrationAfter making a batch of test tubes, break off both ends of several of them with the glass cutte

27、r(4.3) and immerse one end of a tube vertically into each of various solutions containingdifferent chloride ion concentrations. Note the top of the colour change in each tube and markall the tubes in the batch appropriately to give each a scale in mg/l.NOTE Commercial versions of the tubes are avail

28、able for determining the chlorideconcentration over various ranges. A suitable tube is chosen for each test.Unused detection tubes shall be stored in a refrigerator for no longer than two years.4.3 Cutter, for cutting off the ends of the detection tube.4.4 Measuring cylinder, of 250 ml capacity.4.5

29、Beakers, one of 100 ml capacity, two of 250 ml capacity.4.6 Glass stirring rod.4.7 Cotton gauze, chloride-free, measuring approximately 300 mm x 300 mm.4.8 Gloves, made of plastic or rubber.4.9 Adhesive tape.4.10 Tape measure.SANS 8502-5:2008This s tandard may only be used and printed by approved su

30、bscription and freemailing clients of the SABS .ISO ISO 8502-5:1998(E)35 Procedure5.1 Washing the test areaWhile the following test describes a particular swabbing procedure for washing the test area,any of several suitable controlled-washing procedures available may be used if desired.During the wa

31、shing procedure, ensure, by wearing clean plastic or rubber gloves (4.8), that thewash water is not accidentally contaminated.Before starting the washing procedure, an area of the steel surface which has been preparedfor painting shall be identified by the interested parties as suitable for the test

32、. Mark out anactual test area measuring 0,5 m x 0,5 m, or 0,25 m2in total area, the shape depending on thesize and shape of the steel substrate, using the tape measure (4.10) and adhesive tape (4.9).Pour 130 ml of water (4.1) into one of the 250 ml beakers and 20 ml into the 100 ml beaker(see 4.5).

33、Soak the cotton gauze (4.7) in the water in the larger beaker and squeeze some ofthe water out gently by hand. As the gloves must be washed at the very end of the washingprocedure using only a limited quantity of water, users are advised to hold the gauze with thefingertips only. Thoroughly swab the

34、 whole of the test area with the gauze. Allow as littlewater as possible to drip from the gauze or to run off the test area. Remove the water from thesurface with the gauze, squeezing the washings into the other 250 ml beaker. Repeat theswabbing procedure four times (i.e. for a total of five times),

35、 changing the direction of wipingeach time.On completion of the fifth swabbing procedure, place the gauze in the larger beaker. Withgreat care rinse the glove fingertips in the water in the small beaker and subsequently pour thisrinse water into the larger beaker. Mix the contents of the larger beak

36、er by stirring with theglass stirring rod (4.6).NOTE The Bresle method specified in ISO 8502-6 may be used for extraction of thechloride in combination with analysis by the ion detection tube method if the chloridesurface density to be determined is higher than 100 mg/m2(10 g/cm2).5.2 Determination

37、of the chloride concentration in the test solutionCut both ends of the detection tube with the cutter (4.3). Immerse one end of tube in the testsolution. Hold the tube vertically with the end at or near the bottom of the beaker. When thesolution reaches the top plug, read off the chloride concentrat

38、ion in the test solution, in mg/1,from the scale, as indicated by a slight change in the colour where the chromate has reactedwith the chloride in the solution.If the solution fails to reach the top of the tube within 5 min, discard the tube and repeat theprocedure with a fresh tube.Carry out a tota

39、l of five determinations using five fresh tubes. Note each individualmeasurement and the average of the three middle values obtained.SANS 8502-5:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 8502-5:1998(E) ISO4No temperature correct

40、ion is required if the test is carried out between 5 C and 80 C. Thetest shall not be carried out below 5 C.NOTE The presence of bromide, iodide or cyanide ions will give slightly higherreadings. Sulfate, nitrate or iron ions can affect the readings by up to 10 %. Variationsin pH of the solution wit

41、hin the range 4-13 will not affect the readings.During the procedure, avoid contaminating the solution with chloride from hands, gloves andthe cotton used for swabbing. A blank test may be carried out to determine the amount of suchcontamination.5.3 Verification testTo verify tube calibration, take

42、three tubes per production lot and use them to test a solutionof known chloride concentration close to that of the test solution already analysed. Take theaverage of the two closest values as the result of the verification test. The accuracy of theaverage obtained for the test solution concentration

43、 shall be within 15 %.The chloride ion concentration in the test solution shall be within the range 50 mg/l to100 mg/l.6 Expression of resultsCalculate the amount of chloride extracted N, expressed as milligrams of sodium chloride persquare metre of surface, using the following equation:NVMAA= (NaCl

44、)(Cl)Clrr r1whereV is the volume, in litres, of water used;Clis the chloride ion concentration, in milligrammes per litre, in the larger beaker;Mr(NaCl) is the molecular mass of sodium chloride (= 58,5);Ar(Cl) is the atomic mass of chlorine (= 35,5);A is the test area, in square metres (= 0,25 m2).S

45、ANS 8502-5:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO ISO 8502-5:1998(E)57 Test reportThe test report shall contain at least the following information:a) all details necessary to identify the steel surface tested;b) a reference t

46、o this part of ISO 8502 (ISO 8502-5);c) the manufacturer and batch number of the detection tubes used, and the type of tube;d) the results of the verification test on the detection tubes;e) the chloride ion concentration in the test solution, expressed as:1) the individual values for all five tubes,

47、2) the average of the three middle values;f) the result of the test as indicated in clause 6;g) any deviation from the test method specified, in particular details of any otherwashing method used;h) the date of the test.SANS 8502-5:2008 Standards South AfricaThis s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .