1、Designation: D4399 05 (Reapproved 2017)Standard Test Method forMeasuring Electrical Conductivity of Electrocoat Baths1This standard is issued under the fixed designation D4399; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the elec-trical conductivity of electrocoat baths or ultrafiltrate
3、samplesusing commercially available equipment.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility
4、of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the De
5、cision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1125 Test Methods for Electrical Conductivity and Resis-tivity of WaterD1193 S
6、pecification for Reagent Water3. Summary of Test Method3.1 A specimen is placed in a conductivity cell, or con-versely a conductivity cell is placed in an electrocoat material,and the cell is connected to a conductivity bridge. Theelectrical conductivity is read directly off the meter of thebridge a
7、s the instantaneous peak reading.4. Significance and Use4.1 The conductivity of electrocoat baths results from thepresence of ionic species in the bath, which come from thevehicle and from the presence of impurities present as ioniz-able acids, bases, salts, or combinations of these. The presenceof
8、excessive amounts of ionic impurities is detrimental to theapplication and performance properties of electrocoatingpaints. The test is suitable for use in research, production,quality control and electrocoat bath process control.4.2 Other related methods for determining the electricalconductivity of
9、 water are described in Test Methods D1125.5. Apparatus5.1 Conductivity BridgeBattery, or AC/DC line-operated,capable of providing a conductivity reading almost instanta-neously.5.2 Conductivity CellDip or fill type, cell constant of 1.0.5.3 ThermometerAny type capable of 0.5C accuracywith a 2 to 32
10、C range.5.4 Measuring VesselAny suitable cylindrical containercapable of holding sufficient electrocoat sample to cover theelectrodes of the conductivity cell, and allowing at least 25 mmbetween the conductivity cell and the sides of the vessel.6. Reagents and Materials6.1 Purity of WaterReferences
11、to water shall be under-stood to mean water conforming to Type II of SpecificationD1193.6.2 Cleaning SolventAn appropriate solvent for the elec-trocoat material under measurement.7. Sampling and Sample Preparation7.1 The sample should be obtained while the electrocoatbath is under proper circulation
12、 so that a uniform sample isobtained. In the case of an ultrafiltrate, the material should bethoroughly mixed or stirred prior to sampling to ensureuniformity.7.2 After sampling and prior to removing a test specimen, itis mandatory that the samples be shaken or stirred until they arehomogeneous and
13、free of any settled material. This is particu-larly important if there is a delay between sampling the bathand performing the test on the bath materials. The absence ofsettled material can be ascertained visually (in a transparentcontainer) or by inserting a spatula, scraping the bottom of thecontai
14、ner and making sure that there is no settled matter. Shake1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edit
15、ion approved July 1, 2017. Published July 2017. Originally approvedin 1984. Last previous edition approved in 2011 as D4399 05 (2011). DOI:10.1520/D4399-05R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of
16、ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized p
17、rinciples on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1or stir the sample until specimens are taken for measurement;THIS POINT
18、 IS VERY IMPORTANT.8. Procedure8.1 Calibrate the conductivity cell prior to use following themanufacturers instructions.8.2 Rinse the measuring container several times with por-tions of the electrocoat material under test.8.3 Take a representative portion of the electrocoat bath orpermeate sample an
19、d place it in the measuring container. Stirthe specimen thoroughly to keep it from settling.8.4 Adjust the temperature of the specimen to 25 6 0.5C.This is very important, since temperature differences causedisagreements in results and are a major source of error in thesemeasurements.8.5 Immerse the
20、 cell in the specimen, and move the cell upand down several times to displace any air bubbles from insidethe cell. Hold the cell in a slightly inclined position in thecenter of the container with the vents at the top of the cellhousing beneath the surface of the liquid. If a fill-type cell isused, p
21、our the specimen into the conductivity cell.8.6 Read and record the conductivity as described in themanufacturers instructions regarding the use of the instru-ment. Avoid measuring times longer than 15 s to preventelectrocoat sample deposition on the cell electrodes. Perform asecond measurement on a
22、nother specimen, repeating steps in8.3 and 8.6. Calculate the mean of both measurements.8.7 Take extreme care to prevent contamination of thesample and equipment. Rinse the cell with deionized water andan appropriate solvent immediately after use. Keep cell cleanand do not allow the dry electrocoat
23、sample to accumulate onthe interior of the cell.9. Report9.1 Report the conductivity in terms of microsiemens (ormicroohms per centimetre) to the nearest 1 % of the deter-mined conductivity.10. Precision and Bias10.1 PrecisionIn an interlaboratory study of this testmethod, with five laboratories mea
24、suring five electrocoat bathsamples with conductivities ranging from 720 to 1750 S/cm(microohms/cm), the intralaboratory coefficient of variationwas found to be 2.6 % relative at 25 df, and the interlaboratorycoefficient of variation 4.2 % relative at 20 df. Based on thesecoefficients, the following
25、 criteria should be used for judgingthe acceptability of results at the 95 % confidence level:10.1.1 RepeatabilityTwo results, each the mean of dupli-cate determinations, obtained by the same operator on differentdays should be considered suspect if they differ by more than7.6 % relative.10.1.2 Repr
26、oducibilityTwo results, each the mean of du-plicate determinations, obtained by operators in different labo-ratories should be considered suspect if they differ by morethan 16.5 % relative.10.2 BiasBias cannot be determined for this methodbecause there are no accepted standards for the electricalcon
27、ductivity of electrocoat baths or ultrafiltrate samples.11. Keywords11.1 electrocoat bath; electroconductivityASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised
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30、u feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual
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