1、NACE SP0508-2017 Item No. 21134 Revised: 2017-11-15 Revised: 2010-08-19 Approved 2008-11-07 ISBN 1-57590-222-2 2017, NACE International 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 indiv
2、idual members who have reviewed this document, its scope, and provisions. Its acceptance does not in any respect preclude 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 sta
3、ndard. Nothing contained in this NACE International stan- dard is to be construed as granting any right, by implication or otherwise, to manufacture, sell, or use in connection with any method, apparatus, or product covered by Letters Patent, or as indemnifying or protecting anyone against liability
4、 for infringement of Let- ters Patent. This standard represents minimum requirements and should in no way be interpreted 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 circum- stances may n
5、egate the usefulness of this standard in specific instances. NACE Interna- tional assumes no responsibility for the interpretation or use of this standard by other parties and accepts responsibility for only those official NACE International interpreta- tions issued by NACE International in accordan
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7、ty in relation to this standard prior to its use. This NACE International standard may not necessarily address all potential health and safety problems or environmental haz- ards associated with the use of materials, equipment, and/or operations detailed or re- ferred to within this standard. Users
8、of this NACE International standard are also respon- sible for establishing appropriate health, safety, and environmental protection practices, in consultation with appropriate regulatory authorities if necessary, to achieve compli- ance with any existing applicable regulatory requirements prior to
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10、ndard no later than five years from the date of initial publication and subse- quently from the date of each reaffirmation or revision. The user is cautioned to obtain the latest edition. Purchasers of NACE standards may receive current information on all standards and other NACE publications by con
11、tacting the NACE FirstService Depart- ment, 15835 Park T en Place, Houston, TX 77084-5145 (telephone +1 281-228-6200). ABSTRACT The purpose of this standard practice is to define a method that shows equivalence of other methods for measuring the level of contamination of soluble salts on surfaces to
12、 the Bresle patch method defined by ISO 8502-9. This standard practice provides a way to establish equivalence by testing and comparing results of the tests to meet estab- lished criteria that would be achieved using the method specified in ISO 8502-9. Equiva- lence is evaluated at three salt levels
13、 (30 mg/ m 2 , 50 mg/m 2 , and 85 mg/m 2 ) on three sur- face conditions (grit blasted steel, zinc sili- cate preconstruction primer on steel, and rusted steel). KEYWORDS ISO 8502-9, salt, measurement, test, con- tamination, equivalence, Bresle, TG 3922 SP0508-2017 NACE International Foreword The pu
14、rpose of this standard practice is to define a method that 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. 1This standard practice provides a way to establish equivalence by testing and comp
15、aring results of the tests to meet estab- lished criteria that would be achieved using the method specified in ISO 8502-9. Equiva- lence is evaluated at three salt levels (30 mg/m 2 , 50 mg/m 2 , and 85 mg/m 2 ) on three sur- face conditions (grit blasted steel, zinc silicate preconstruction primer
16、on steel, and rusted steel). This standard is intended for use by engineers, 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 s
17、how such equivalence to the results obtained using ISO 8502-9. The definition of equivalence as used in this standard is “an alternative tool, method, or procedure that predictably and reliably provides the same measurement values as test- ing in accordance with ISO 8502-9 would provide under the sa
18、me circumstances, i.e., that measures the total salt contamination 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
19、 of the equivalence of a method must be made in a laboratory. This standard was originally issued in 2008 and revised in 2010 and 2017 by T ask Group (TG) 392, “Measurement of Soluble Salts on Marine Structures.” TG 392 is administered by Specific T echnology Group (STG) 44, “Marine Corrosion: Ships
20、 and Structures,” and sponsored by STG 04, “Coatings and Linings, Protective: Surface Preparation.” It is is- sued by NACE International under the auspices of STG 44. In NACE standards, the terms shall, must, should, and may are used in ac- cordance with the definitions of these terms in the NACE Pu
21、blications Style Manual. The terms shall and must are used to state a requirement, and are con- sidered mandatory. The term should is used to state something good and is rec- ommended, but is not considered man- datory. The term may is used to state something considered optional. (1)International Or
22、ganization for Standardization (ISO), 1 ch. de la Voie-Creuse, Case postale 56, CH-1211 Geneva 20, Switzerland.NACE International SP0508-2017 3 NACE International Standard Practice SP0508 Methods of Validating Equivalence to ISO 8502-9 on Measurement of the Levels of Soluble Salts 1. General 4 2. Te
23、st Methods .5 3. Reporting9 References .9 Appendix A: Standard Method for Performance of Soluble Salts Testing in Accordance with ISO 8502-9 (Mandatory) .10 Appendix B: Rationale for Specification Limits (Nonmandatory) 13 Appendix C: Recommended Methods for Applying Salt Solution to Steel Panels (No
24、nmandatory) .15 Figures A1: Peeling Bresle Patch 11 A2: Pressing Bresle Patch 11 A3: Filled Syringe .12 A4: Inserting Syringe Needle into Patch .12 A5: Rubbing Bresle Patch 12 A6: Reading Specific Conductivity16 Tables 1: Test Conditions.6 B1: Standard Deviations .144 SP0508-2017 NACE International
25、Section 1: General1.1 ISO 8502-9 Range of Variance 1.1.1 The assessment 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
26、for the conductometric determination of water-soluble salts in accordance with ISO 8502-9. As a part of that method, the extraction of soluble salt contaminants for analysis is performed in accordance with ISO 8502-6 2 the Bresle method. The field execution of this method involves using a syringe to
27、 inject deionized water into the Bresle patch, washing the substrate surface inside the patch, then extracting the test water for direct measurement of specific conductivity. Details of this procedure are provided in Appendix A (mandatory). Once a specific conduc- tivity value is determined by the c
28、onductivity meter, expressed as microsiemens per centimeter (S/cm), ISO 8502-9 provides a procedure to calculate the equiv- alent 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
29、 potential variances during the field evaluation. Some ex- amples include background salt contamination in the Bresle patch itself, the sen- sitivity 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
30、, and general operator experience. These individual process variances combine to cre- ate an overall variance in the ISO 8502-9 test method. 1.1.3 The test method defined in ISO 8502-9 allows certain execution param- eters of the test (e.g., size of adhesive patch, volume of test solution, and time
31、of dissolution of salts inside the adhesive patchthe dwell time) to vary. This stan- dard adopted best 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 n
32、ot perfect. Hence, a dwell time of 90 seconds was adopted in Appendix A. For the purpose of defin- ing equivalence, the procedure in Appendix A shall be used to create the refer- ence values to which the candidate method will be validated. 1.1.4 Bresle patches from different manufacturers or manufac
33、turing lots may have different levels of background contamination. Specifications for salt contam- ination include the contribution of this background contamination so that the op- erator in the field does not have to subtract a background value to report the test results. Appendix A therefore inclu
34、des a provision to correct the ISO 8502-9 test results to a consistent offset contributed by Bresle patch background contamina- tion 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 vari
35、ance in ISO 8502-6 and 8502-9 has been demon- strated by extensive laboratory tests. 3The precision of a single ISO 8502-9 test result was determined to be 8.2 mg/m 2in the salt level range of 30 to 80 mg/m 2 . The absolute variance, and not the relative or percent variance, was found to be constant
36、 in this range. See Appendix B (nonmandatory) for details about these tests and the data analysis. 1.1.6 Any equivalent 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 wo
37、uld be produced by following the procedure in ISO 8502-9. NACE International SP0508-2017 5 1.1.7 The objective of this standard is to determine whether methods other than the Bresle method are suitable alternatives for measuring salt contamination in the field. Although tests may be performed on fla
38、t, horizontal surfaces for ease of use, each method should also be capable of performing measurements on vertical and overhead surfaces. When such measurements cannot be performed on vertical or overhead surfaces, this limitation must be noted in the validation report (Section 3). 1.2 Reasons for Sa
39、lt Measurement 1.2.1 It is well known that applying protective coatings over salt contamination may cause degradation of the coating/substrate interface. This may lead to corro- sion of the substrate and detachment of the coating. These effects reduce the expected service life of the coating. 4 1.2.
40、2 Different salt ions influence the rate of corrosion under coatings differ- ently. However, most common salts promote corrosion 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 as water transmits into and through the coa
41、ting. The osmotic pressure generated can cause blisters to form in the coating. 1.2.4 The general relationship between the amount of salt contamination un- der the coating film and consequent deterioration of the performance may be considered to be linear. 1.2.5 Although virtually unobtainable, a ze
42、ro measure of salt contamination may be considered the only “safe” level before application of coating films. There- fore, the maximum quantity of salt contamination allowed in a specification should be based on a holistic risk/cost analysis. Section 2: T est Methods 2.1 Test Considerations 2.1.1 Fo
43、r the purposes of this standard, all references to performing a test by ISO 8502-9 shall mean performing a test by following the 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
44、 a single math- ematical correction factor to produce equivalence of alternative test results to those produced by ISO 8502-9. 2.1.3 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
45、failure of the test method that can be verified independently of the final test result. For example, ISO 8502-9 failures can include 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 oper- at
46、or to comply with the test method.6 SP0508-2017 NACE International 2.1.3.2 Data removed from the analysis as a result of failures of this nature must be documented in the final report, including the reason for deeming them failed measurements. 2.2 Preparation of Test Panels 2.2.1 Surface Conditions
47、of Test Panels: Laboratory tests shall be performed on carbon steel test panels (e.g., standard grade hot-rolled carbon steel in accor- dance with ASTM (2)A366). 5Appendix C (nonmandatory) provides recommenda- tions on the preparation of test panels. Three surface conditions shall be tested: 2.2.1.1
48、 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 8501-1. 6 2.2.1.3 Surface Condition C: new steel blasted to Sa 2 in accor- dance with ISO 8501-1, using aluminum oxide to achieve a surface pro- f
49、ile of 50 to 75 m (2.0 to 3.0 mil). 2.2.2 Salt Level: Three target levels of salt contamination shall be tested: 2.2.2.1 30 mg/m 2 2.2.2.2 50 mg/m 2 2.2.2.3 85 mg/m 2 2.2.3 Test Condition: A test condition is defined in this standard as a unique combination of surface condition and salt level. Laboratory tests shall be per- formed at the five test conditions listed in Table 1: Table 1 Test Conditions Test Condition Surface Condition Target Salt Level (mg/m 2 ) 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 prepare
