1、 Standard Practice Methods of Validating Equivalence to ISO 8502-9 on Measurement of the Levels of Soluble Salts This NACE International standard represents a consensus of those individual members who have reviewed this document, its scope, and provisions. Its acceptance does not in any respect prec
2、lude anyone, whether he or she has adopted the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not in conformance with this standard. Nothing contained in this NACE International standard is to be construed as granting any right, by implication
3、 or otherwise, to manufacture, sell, or use in connection with any method, apparatus, or product covered by Letters patent, or as indemnifying ore protecting anyone against liability for infringement of Letters Patent. This standard represents minimum requirements and should in no way be interpreted
4、 as a restriction on the use of better procedures or materials. Neither is this standard intended to apply in all cases relating to the subject. Unpredictable circumstances may negate the usefulness of this standard in specific instances. NACE International assumes no responsibility for the interpre
5、tation or use of this standard by other parties and accepts responsibility for only those official NACE International interpretations issued by NACE International in accordance with its governing procedures and policies which preclude the issuance of interpretations by individual volunteers. Users o
6、f this NACE international standard are responsible for reviewing appropriate health, safety, environmental, and regulatory documents and for determining their applicability in relation to this standard prior to its use. This NACE International standard may not necessarily address all potential healt
7、h and safety problems or environmental hazards associated with the use of materials, equipment, and/or operations detailed or referred to within this standard. Users of this NACE International standard are also responsible for establishing appropriate health, safety, and environmental protection pra
8、ctices, in consultation with appropriate regulatory authorities if necessary, to achieve compliance with any existing applicable regulatory requirements prior to the use of this standard. CAUTIONARY NOTICE: NACE international standards are subject to periodic review, and may be revised or withdrawn
9、at any time in accordance with NACE technical committee procedures. NACE International requires that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of initial publication. The user is cautioned to obtain the latest edition. Purchasers of NACE In
10、ternational standards may receive current information on all standards and other NACE International publications by contacting the NACE International First Service Department, 1440 South Creek Dr., Houston, Texas 77084-4907 (telephone +1 281-228-6200). Revised 2010-08-19 Approved 2008-11-07 NACE Int
11、ernational 1440 South Creek Dr. Houston, Texas 77084-4906 +1 281-228-6200 2010, NACE International An American National Standard Approved December 23, 2010 ANSI/NACE SP0508-2010 Item No. 21134 SP0508-2010 NACE International i _ Foreword The purpose of this standard practice is to define a method tha
12、t shows equivalence of other methods for measuring the level of contamination of soluble salts on surfaces to the Bresle patch method defined by ISO(1) 8502-9.1 This standard practice provides a way to establish equivalence by testing and comparing results of the tests to meet established criteria t
13、hat would be achieved using the method specified in ISO 8502-9. Equivalence is evaluated at three salt levels (30 mg/m2, 50 mg/m2, and 85 mg/m2) on three surface conditions (grit blasted steel, zinc silicate preconstruction primer on steel, and rusted steel). This standard is intended for use by eng
14、ineers, specification writers, test equipment suppliers, contractors, and anyone testing for soluble salts on surfaces using ISO 8502-9 and considering use of equivalent methods for this purpose. It provides a standard method to show such equivalence to the results obtained using ISO 8502-9. The def
15、inition of equivalence as used in this standard is “an alternative tool, method, or procedure that predictably and reliably provides the same measurement values as testing in full accordance with ISO 8502-9 would provide under the same circumstances, i.e., that measures the total salt contamination
16、amount at an extraction rate equal to the method given in ISO 8502-9, and presents the result as total surface density of the salts as described in ISO 8502-9, expression of results, and accuracy of the determination.” The validation of the equivalence of a method must be made in a laboratory. This
17、standard was originally issued in 2008 and revised in 2010 by Task Group (TG) 392, “Measurement of Soluble Salts on Marine Structures.” TG 392 is administered by Specific Technology Group (STG) 44, “Marine Corrosion: Ships and Structures,” and sponsored by STG 04, “Coatings and Linings, Protective:
18、Surface Preparation.” It is issued by NACE International under the auspices of STG 44. In NACE standards, the terms shall, must, should, and may are used in accordance with the definitions of these terms in the NACE Publications Style Manual. The terms shall and must are used to state a requirement,
19、 and are considered mandatory. The term should is used to state something good and is recommended, but is not considered mandatory. The term may is used to state something considered optional. _ _ (1)International Organization for Standardization (ISO), 1 ch. de la Voie-Creuse, Case postale 56, CH-1
20、211 Geneva 20, Switzerland. SP0508-2010 ii NACE International _ NACE International Standard Practice Methods of Validating Equivalence to ISO 8502-9 on Measurement of the Levels of Soluble Salts Contents 1. General 1 2. Test Methods 2 3. Reporting . 5 References 5 Appendix A: Standard Method for Per
21、formance of Soluble Salts Testing in Accordance with ISO 8502-9 (Mandatory) . 6 Appendix B: Rationale for Specification Limits (Nonmandatory) 9 Appendix C: Recommended Preparation of Test Panels and Methods for Applying Salt Solution to Test Panels (Nonmandatory) . 11 Figures: Figure A1: Peeling Bre
22、sle Patch 7 Figure A2: Pressing Bresle Patch 7 Figure A3: Filled Syringe . 8 Figure A4: Inserting Syringe Needle into Patch 8 Figure A5: Rubbing Bresle Patch 8 Figure A6: Reading Conductivity . 8 _ SP0508-2010 NACE International 1 _ Section 1: General 1.1 ISO 8502-9 Range of Variance 1.1.1 The asses
23、sment and determination of surface contamination (by salts) prior to application of protective coatings is critical to their service life expectancy. Determination of the level of surface cleanliness is performed using a field method for the conductometric determination of water-soluble salts in acc
24、ordance with ISO 8502-9. As a part of that method, the extraction of soluble salt contaminants for analysis is performed in accordance with ISO 8502-62the Bresle method. The field execution of this method involves using a syringe to inject deionized water into the Bresle patch, washing the substrate
25、 surface inside the patch, then extracting the test water for direct measurement of conductivity. Details of this procedure are provided in Appendix A (mandatory). Once a conductivity value is determined by the conductivity meter, expressed as microsiemens per centimeter (S/cm), ISO 8502-9 provides
26、a procedure to calculate the equivalent mass of the surface concentration as total surface density of the salts. 1.1.2 Step-by-step execution of the ISO 8502-6 and ISO 8502-9 test methods introduces a number of potential variances during the field evaluation. Some examples include background salt co
27、ntamination in the Bresle patch itself, the sensitivity and resolution of the conductivity meter, cycle time of the test water inside the Bresle patch, human errors in measuring and injecting the test water, and general operator experience. These individual process variances combine to create an ove
28、rall variance in the ISO 8502-9 test method. 1.1.3 The test method defined in ISO 8502-9 allows certain execution parameters of the test (e.g., size of adhesive patch, volume of test solution, and time of dissolution of salts inside the adhesive patchthe dwell time) to vary. This standard adopted be
29、st practices and has set the parameters in Appendix A. With a dwell time at a minimum of 90 seconds, the variance from operator error was found to be reduced dramatically when the operator timing is not perfect. Hence, a dwell time of 90 seconds was adopted in Appendix A. For the purpose of defining
30、 equivalence, the procedure in Appendix A shall be used to create the reference values to which the candidate method will be validated. 1.1.4 Bresle patches from different manufacturers or manufacturing lots may have different levels of background contamination. Specifications for salt contamination
31、 include the contribution of this background contamination so that the operator in the field does not have to subtract a background value to report the test results. Appendix A therefore includes a provision to correct the ISO 8502-9 test results to a consistent offset contributed by Bresle patch ba
32、ckground contamination so that this standard gives consistent results when tests are performed with Bresle patches from different manufacturers or manufacturing lots. 1.1.5 The range of variance in ISO 8502-6 and 8502-9 has been demonstrated by extensive laboratory tests.3The precision of a single I
33、SO 8502-9 test result was determined to be 8.2 mg/m2in the salt level range of 30 to 80 mg/m2. The absolute variance, and not the relative or percent variance, was found to be constant in this range. See Appendix B (nonmandatory) for details about these tests and the data analysis. 1.1.6 Any equival
34、ent tools, methods, or procedures must show that they meet the same criteria, thereby providing the same measures of soluble salt level, and be within the same range of variance, as would be produced by following the procedure in ISO 8502-9. 1.1.7 The objective of this standard is to determine wheth
35、er methods other than the Bresle method are suitable alternatives for measuring salt contamination in the field. Although tests may be performed on flat, horizontal surfaces for ease of use, each method should also be capable of performing measurements on vertical and overhead surfaces. When such me
36、asurements cannot be performed on vertical or overhead surfaces, this limitation must be noted in the validation report (Section 3). 1.2 Reasons for Salt Measurement SP0508-2010 2 NACE International 1.2.1 It is well known that applying protective coatings over salt contamination may cause degradatio
37、n of the coating/substrate interface. This may lead to corrosion of the substrate and detachment of the coating. These effects reduce the expected service life of the coating.41.2.2 Different salt ions influence the rate of corrosion under coatings differently. However, most common salts promote cor
38、rosion and have a negative effect on the service life of coatings. 1.2.3 Salts on a surface under a coating can create an osmotic cell, drawing water into and through the coating. The osmotic pressure generated can cause blisters to form in the coating. 1.2.4 The general relationship between the amo
39、unt of salt contamination under the coating film and consequent deterioration of the performance may be considered to be linear.51.2.5 Although virtually unobtainable, a zero measure of salt contamination may be considered the only “safe” level before application of coating films. Therefore, the max
40、imum quantity of salt contamination allowed in a specification should be based on a holistic risk/cost analysis. _ Section 2: Test Methods 2.1 Test Considerations 2.1.1 For the purposes of this standard, all references to performing a test by ISO 8502-9 shall mean performing a test by following the
41、test method in Appendix A. 2.1.2 Alternative test methods may produce raw test results with values that are different from those produced by ISO 8502-9. It is valid to use a single mathematical correction factor to produce equivalence of alternative test results to those produced by ISO 8502-9. 2.1.
42、3 Failed measurements may be removed from the data sets that are used for data analysis in Paragraph 2.4. 2.1.3.1 In this standard, “failed measurement” is defined as a failure of the test method that can be verified independently of the final test result. For example, ISO 8502-9 failures can includ
43、e leaking of water from the cell during the test, conductivity meter failing a conductivity calibration check using a known standard solution, or failure of the operator to comply with the test method. 2.1.3.2 Data removed from the analysis as a result of failures of this nature must be documented i
44、n the final report, including the reason for deeming them failed measurements. 2.2 Preparation of Test Panels 2.2.1 Surface Conditions of Test Panels: Laboratory tests shall be performed on carbon steel test panels (e.g., standard grade copper-free hot-rolled carbon steel in accordance with ASTM(2)A
45、366). Appendix C (nonmandatory) provides recommendations on the preparation of test panels. Three surface conditions shall be tested: 2.2.1.1 Surface Condition A: zinc shop-primer-coated new steel. 2.2.1.2 Surface Condition B: non-shop-primed steel rusted to rust grade C in accordance with ISO 8501-
46、1.7(2)ASTM International (ASTM), 100 Barr Harbor Dr., West Conshohocken, PA 19428-2959. SP0508-2010 NACE International 3 2.2.1.3 Surface Condition C: new steel blasted to Sa 2 in accordance with ISO 8501-1, using aluminum oxide to achieve a surface profile of 50 to 75 m (2.0 to 3.0 mil). 2.2.2 Salt
47、Level: Three target levels of salt contamination shall be tested: 2.2.2.1 30 mg/m22.2.2.2 50 mg/m22.2.2.3 85 mg/m22.2.3 Test Condition: A test condition is defined in this standard as a unique combination of surface condition and salt level. Laboratory tests shall be performed at the five test condi
48、tions listed in Table 1: Table 1 Test Conditions Test Condition Surface Condition Target Salt Level(mg/m2) 1 A 50 2 B 50 3 C 50 4 C 30 5 C 85 2.2.4 Test Panel Area Required: A sufficient number and area of test panels shall be prepared to accomplish all the testing required in this standard. The minimum test panel dimensions shall be 200 x 150 mm (8 x 6 in). No area of test panel may be measured twice for this protocol. Test panels shoul
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