ASTM D5682-2008 431 Standard Test Methods for Electrical Resistivity of Liquid Paint and Related Materials《液体涂料及有关材料电阻率的标准试验方法》.pdf

1、Designation: D 5682 08Standard Test Methods forElectrical Resistivity of Liquid Paint and Related Materials1This standard is issued under the fixed designation D 5682; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las

2、t revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 These test methods cover the determination of specificresistance (resistivity) of liquid paints, solvents, and otherflui

3、ds in the range of 0.6 to 2640 MV-cm.1.2 Test Method A describes a procedure for making resis-tance tests with a commonly used paint application testassembly (Fig. 1 and Fig. 2).1.3 Test Method B describes a procedure for making resis-tance tests with a conductivity meter (Fig. 3).1.4 The values sta

4、ted in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety an

5、d health practices and determine the applica-bility of regulatory limitations prior to use.2. Terminology2.1 Definitions:2.1.1 specific resistance (resistivity), nthe ratio of the d-cpotential gradient in volts per centimetre paralleling the currentflow within the specimen to the current density in

6、amperes persquare centimetre at a given instant of time and underprescribed conditions.2.1.1.1 DiscussionThis is numerically equal to the resis-tance between opposite faces of a centimetre cube of the liquid.The units are ohm centimetres (or megohm centimetres).2.2 Definitions of Terms Specific to T

7、his Standard:2.2.1 kilohm (KV), nresistance value equal to 1000 V(103).2.2.2 megohm (MV), nresistance value equal to1 000 000 V (106).2.2.3 ohm-centimetre (or megohm-centimetre), nunit ofspecific resistance (resistivity).1These test methods are under the jurisdiction of ASTM Committee D01 onPaint an

8、d Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D01.24 on Physical Properties of Liquid Paints electrical resistance; electrical re-sistivity; electrostatic spray applicationcompatibility; paintapplication test assembly; specific resistanceAPPENDIX(No

9、nmandatory Information)X1. TESTING THE PROBE (CELL CONSTANT DETERMINATION)X1.1 These cells depend on concentricity of the inner andouter section for accuracy and repeatability. The cell constantmay be tested by the following method. Both cells haveidentical cell constants by design, so may be tested

10、 in samemanner. The main reason for doing this is to determine whetherthe cell is in good condition, clean, and operating properly. Ifthe cell is dirty or damaged, it will not give the correct cellconstant.X1.2 Obtain a standard solution of approximately 1000V/cm.X1.3 Measure the resistance of the s

11、tandard solution (inohms) using the probe and an ohmmeter with full scale readingof about 25 V, since the test meters normally used in thesemethods are not suitable for measuring this low value ofresistance.D5682083X1.4 The cell constant may be found by substituting in thefollowing equation:K 5 P/R

12、X1.1)where:K = the cell constant in cm,P = the resistance in MV-cm, andR = the resistance in MV.X1.5 This value is typically 132, but may vary slightlybecause of manufacturing tolerances, or slight damage while inuse. If the cell constant is 133, reclean the cell andrecheck the constant. If it is s

13、till outside the range 128 to 133,then the outer sleeve probably has been damaged and must bereplaced.SUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to this standard since the last issue(D 5682 - 95 (2002) that may impact the use of this standard. (Approved June 1, 2

14、008.)(1) Information on specific suppliers of instruments has beenremoved in keeping with ASTM policy.(2) The section on Apparatus has been split in two and movedto the two different test methods.(3) The section on Reagents and Materials has been renum-bered.(4) A sentence has been added to the Appa

15、ratus section forMethodAindicating that the meter that is currently available isdigital.(5) A diagram of the digital apparatus for Method A has beenadded (Figure 2) and the previous Figure 2 has been renumberto Figure 3.(6) Several typographical errors have been corrected.ASTM International takes no

16、 position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own respons

17、ibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed t

18、o ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the add

19、ress shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D5682084