1、Designation: D 1903 08Standard Practice forDetermining the Coefficient of Thermal Expansion ofElectrical Insulating Liquids of Petroleum Origin, andAskarels1This standard is issued under the fixed designation D 1903; the number immediately following the designation indicates the year oforiginal adop
2、tion or, in the case of revision, the year 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 practice covers the determination of the coef-ficientof thermal exp
3、ansion of electrical insulating liquids of petro-leum origin, and askarels, containing PCBs (polychlorinatedbiphenyls), when used as an insulating or cooling medium, orboth, in cables, transformers, oil circuit breakers, capacitors, orsimilar apparatus.1.2 The values stated in SI units are to be reg
4、arded 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 of the user of this standard to establish appro-priate safety and health practices and determ
5、ine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 941 Test Method for Density and Relative Density (Spe-cific Gravity) of Liquids by Lipkin Bicapillary Pycnom-eter3D 1250 Guide for Use of the Petroleum MeasurementTablesD 1298 Test Method for D
6、ensity, Relative Density (SpecificGravity), or API Gravity of Crude Petroleum and LiquidPetroleum Products by Hydrometer MethodD 1810 Test Method for Specific Gravity of Askarels (Dis-continued 2001)33. Terminology3.1 Definition of Term Specific to This Standard:3.1.1 coeffcient of thermal expansion
7、 of a liquid, nthechange in volume per unit volume per degree change intemperature. It is commonly stated as the average coefficientover a given temperature range.4. Significance and Use4.1 Knowledge of the coefficient of thermal expansion of aliquid is essential to compute the required size of a co
8、ntainer toaccommodate a volume of liquid over the full temperaturerange to which it will be subjected. It is also used to computethe volume of void space that would exist in an inelastic devicefilled with the liquid after the liquid has cooled to a lowertemperature.5. Procedure for Liquids of Petrol
9、eum Origin5.1 The coefficient of thermal expansion used in GuideD 1250, is 0.00040/F for the temperature range from 17.7 to65.5C (0 to 150F), and petroleum oils ranging from 15.0 to34.9API gravity or 0.9659 to 0.8504 relative density (specificgravity). In the preparation of these tables for relative
10、 density(specific gravity) values above 0.600, it has been assumed forpurposes of standardization that all crude petroleum andpetroleum products have uniform coefficients of expansion inthe same temperature ranges. When the required accuracy ofresults falls within these assumptions, this value for c
11、oefficientof expansion may be used.5.2 If closer approximation than that indicated in 5.1 isrequired, the coefficient of thermal expansion may be calcu-lated by determining observed relative densities (specificgravities). Determine the relative densities at any two tempera-tures below 90C (194F) and
12、 not less than 5C (9F), normore than 14C (25F) degrees apart by Practice D 1298. Thedifference in the observed relative densities at the two tem-peratures divided by the product of the relative density at thelower temperature and the difference in the two temperaturesmay be used as the average coeff
13、icient of expansion for theobserved temperature range.1This practice is under the jurisdiction of ASTM Committee D27 on ElectricalInsulating Liquids and Gases and is the direct responsibility of SubcommitteeD27.07 on Physical Test.Current edition approved Nov. 1, 2008. Published December 2008. Origi
14、nallyapproved in 1961. Last previous edition approved in 2003 as D 1903 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe
15、 ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Procedure for Askarels6.1 Determine the relative density (specific gravit
16、y) of theaskarel at any two convenient temperatures below 90C(194F) and not less than 14C (25F) apart by Test MethodD 1810. The difference in the observed relative densities at thetwo temperatures divided by the product of the relative densityat the lower temperature and the difference in the two te
17、mpera-tures may be used as the average coefficient of expansion forthe observed temperature range.6.2 If suitably calibrated hydrometers for determining therelative density of an askarel are not available, Test MethodD 941 may be used.7. Calculation7.1 Calculate the coefficient of thermal expansion
18、as fol-lows:Coefficient of thermal expansion 5 S 2 S1!/ST12 T!where:S = relative density (specific gravity) at lower tempera-ture T,S1= relative density (specific gravity) at higher tempera-ture T1,T = lower temperature, andT1= higher temperature.8. Keywords8.1 askarels; density; electrical insulati
19、ng liquids; petro-leum; specific gravity; volumeASTM 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 that determination of the validity of any such patent rights,
20、 and the riskof infringement of such rights, are entirely their own responsibility.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 rev
21、ision of this standard or for additional standardsand should be addressed to 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
22、 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 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).D 1903 082
