1、Manual of Petroleum Measurement StandardsChapter 15Guidelines for the Use of the International System of Units (SI) in the Petroleum and Allied IndustriesFORMERLY API PUBLICATION 2564THIRD EDITION, DECEMBER 2001REAFFIRMED, FEBRUARY 2015Manual of Petroleum Measurement StandardsChapter 15Guidelines fo
2、r the Use of the International System of Units (SI) in the Petroleum and Allied IndustriesMeasurement CoordinationFORMERLY API PUBLICATION 2564THIRD EDITION, DECEMBER 2001REAFFIRMED, FEBRUARY 2015SPECIAL NOTESAPI publications necessarily address problems of a general nature. With respect to partic-u
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16、hington, D.C. 20005.iiiCONTENTSPage15.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115.1 SCOPE AND FIELD OF APPLICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115.2 REFERENCES. . . . . . . . . .
17、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215.3 THE INTERNATIONAL SYSTEM OF UNITS (SI) . . . . . . . . . . . . . . . . . . . . . . . . . 215.3.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、. . . . . 215.3.2 SI Base Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215.3.3 SI Supplementary Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315.3.4 Derived Units. . . . . . . . . . . . . . . . . . .
19、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315.3.5 Other Allowable Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315.3.6 Decimal Multiples and Submultiples of SI Unit . . . . . . . . . . . . . . . . . . . . . 315.3.7 Use of Letter Symbols.
20、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515.4 USE OF CONVERSION TABLES IN SECTION 15.5. . . . . . . . . . . . . . . . . . . . . . . . 515.4.1 Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515
21、.4.2 Corrections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515.4.3 Preferred Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615.4.4 Eqiivalent Units . . . . . . . . . . . . . . . . . . .
22、. . . . . . . . . . . . . . . . . . . . . . . . . . . . 615.4.5 Notation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615.4.6 Signicant Digits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615.4
23、.7 Horsepower, Calorie 2. To encourage uniformity of metric practice andnomenclature within the petroleum industry and3. To facilitate the use of SI in all aspects of the petro-leum industry. Use of this publication by the AmericanPetroleum Institute, its divisions, and its members imple-ments APIs
24、policy and also implements recom-mendations in ISO 10001992, SI Units and Recommen-dations for the Use of Their Multiples and of CertainOther UnitsI1.Production of the rst edition of APIs Publication 2564 in1973 was encouraged by API member companies either oper-ating internationally or participatin
25、g in the activities of theInternational Organization for Standardization (ISO). TheInstitute of Petroleum, Great Britain, (IP) and the CanadianPetroleum Association (CPA) both offered their full endorse-ment and accompanied it with valuable technical support andassistance.The transition to the Inter
26、national System of Units (SI) hasadvanced considerably since 1973. The Metric ConversionAct of 1975 (Public Law 94168) has been enacted,declaring the coordination and planning of increasing use ofthe metric system (SI) in the United States to be governmentpolicy. A notice by the Assistant Secretary
27、of Commerce forScience and Technology in the Federal Registerof October26, 1977 (Volume 42, Number 206, pages 56513 and 56514)interprets and modies SI for the United States. The act alsoprovided for establishing a U.S. Metric Board to coordinatevoluntary conversion. In 1982, the U.S. Metric Board wa
28、sdisbanded. Responsibility for metric coordination wastransferred to the Ofce of Metric Programs in theDepartment of Commerce. The Omnibus Trade andCompetitiveness Act of 1988 amended the Metric ConversionAct of 1975, designating the SI system as the preferredmeasurement system for the United States
29、. In 1991, FederalAgencies were directed to use the Metric System to the extenteconomically feasible and practicable by Executive Order12770, Metric Usage in the Federal government. In additionto the increased activity of the federal government in thiseld, the interpretation of SI also has been deal
30、t withextensively in metric practice guides of various standardsassociations, technical and trade societies, and individualindustries 1 16. The International System of Units (SI) isthe dominate measurement used with the exception of theUnited States. With the arrival of the global market place, it i
31、simperative for US petroleum industry to extend its use of SIand for personnel in the petroleum industry to gain a workingknowledge of SI.The API Metric Transition Committee was formed in 1976to coordinate internal API metric policy and to formulateAPIs policy with regard to government and non gover
32、nmentbodies. One of the Metric Transition Committees rst actionswas the creation of the Subcommittee on Units to review andrevise Chapter 15, Sections I and 2, of the Manual of Petro-leum Measurement Standards. Sections I and 2 had been pub-lished as API Publications 2563 Metric Practice Guide, and2
33、564 Conversion of Operational and Process MeasurementUnits to the Metric (SI) System.At the recommendation of the Subcommittee on Units, theMetric Transition Committee discontinued API Publication2563 and adopted ASTM (American Society for Testing andMaterials) E 38076 3 and ANSI (American National
34、Stan-dards Institute) Z210.11976 2 as the authoritative metricpractice guide. ASTM E 380 has been replaced by IEEE/ASTM SI 10-1997, Standard for use of the International Sys-tem of units (SI): The Modern Metric System14. Because ofspecial interpretations and applications of SI with the petro-leum in
35、dustry, API will continue publishing APIMPMSChapter 15. In preparing Chapter 15, the working group hastried to keep consistent with metric practice as dened by theGeneral Conference on Weights and Measures (abbreviatedCGPM from the ofcial French name), the federal govern-ment, and signicant standard
36、s organizations (such as theAmerican Society for Testing and Materials, the AmericanNational Standards Institute, and related technical societies).However, even among these sources, agreement is not abso-lute on all details of metric practice. Where feasible, Chapter15 has adhered to the policies of
37、 the voluntary standards asso-ciations ASTM and ANSI on all unresolved issues. Where noclear policy has been evident or where the policy was notacceptable to the petroleum industry, this publication has rec-ognized the particular needs of the petroleum industry. Allsuch cases have been specic interp
38、retations of SI, not repudi-ation of the system. Emphasis has been placed on the applica-tion of SI in practice, which has necessitated some departuresfrom rigorous adherence to the idealized, pure SI.15.1 Scope and Field of ApplicationThis publication species the API preferred units for quan-tities
39、 involved in petroleum industry measurements and indi-cates factors for conversion of quantities expressed incustomary units to the API preferred metric units. The quanti-1Numbers in brackets pertain to the references in Appendix C.2 API MANUALOFPETROLEUMMEASUREMENTSTANDARDSties that comprise the ta
40、bles are grouped into convenient cate-gories related to their use. They were chosen to meet the needsof the many and varied aspects of the petroleum industry butalso should be useful in other, similar process industries.15.2 ReferencesThis publication emphasizes the practical application of SI.For a
41、 complete, detailed presentation of SI and the metricpractice on which this publication is based, the reader shouldconsult references 2, 3, or 4.15.3 The International System of Units (SI)15.3.1 GENERALSI is the ofcial abbreviation, in all languages, for theInternational System of Units (Le Systme I
42、nternationaldUnits). The International System is not the old centimeter-gram-second (cgs) system of metric units but is based on themeter, kilogram, and second as the fundamental quantities. SIis considered to be an improvement over the centimeter-gram-second metric system and is used currently or i
43、s beingadopted by most nations of the world.There are two classes of units in SI. The rst consists ofbase units which, by convention, are dimensionally indepen-dent. The second class consists of derived units that areformed by combining base units according to the algebraicrelations linking the corr
44、esponding quantities. Special namesand symbols have been assigned to the commonly used unitsin this class.The coherent nature of SI is preserved by dening allderived combination in terms of unity, thus eliminating con-version factors within the system. As an example, the derivedunit of power, with i
45、ts special name, watt, is dened as 1 jouleof work completed in 1 second of time.15.3.2 SI BASE UNITSThere are seven base units in SI. These units are considered to be dimensionally independent and are precisely dened. Thedenitions are shown below: Quantity Name Symbol Denitionlength meter m The mete
46、r is the length of the path traveled by light in vacuum during a time interval of 1/299 792 458 of a second. (17th GGPM 1983).mass kilogram kg The kilogram is the unit of mass (not force); it is equal to the mass of the international prototype of the kilogram. (1st and 3rd CGPM, 1889 and 1901). This
47、 international prototype, made of platinum-iridium, is kept at the International Bureau of Weights and Measures. A copy of the interna-tional prototype is maintained by the national standards agency of each major country. The kilogram is the only base unit dened by an artifact and is the only base u
48、nit having a prex.time second s The second is the duration of 9 192 631 770 periods of the radiation corre-sponding to the transition between the two hyperne levels of the ground state of the cesium-133 atom. (13th CGPM, 1967)electric current ampere A The ampere is that constant current which, if ma
49、intained in two straight parallel conductors of innite length, of negligible circular cross section, and placed 1 meter apart in vacuum, would produce between these con-ductors a force equal to 2 107newton per meter of length. (CIPM, 1946, Resolution 2 approved by the 9th CGPM, 1948)CHAPTER15GUIDELINESFORTHEUSEOFTHEINTERNATIONALSYSTEMOFUNITS(SI) INTHEPETROLEUMANDALLIEDINDUSTRIES315.3.3 SI SUPPLEMENTARY UNITSThe General Conference has not yet classied certain unitseither as base units or derived units. These SI units areassigned to a
