1、Manual of PetroleumMeasurement StandardsChapter 7Temperature DeterminationFIRST EDITION, JUNE 2001REAFFIRMED, FEBRUARY 2012Manual of PetroleumMeasurement StandardsChapter 7Temperature DeterminationMeasurement CoordinationFIRST EDITION, JUNE 2001REAFFIRMED, FEBRUARY 2012SPECIAL NOTESAPI publications
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13、yright 2001 American Petroleum InstituteFOREWORDThis forward is for information and is not part of this standard. This standard discussesequipment, methods and procedures for determining the temperature of hydrocarbon liquidsunder static and dynamic conditions.This standard contains, and supersedes,
14、 information that was formally contained in thefollowing API Manual of Petroleum Measurement Standards(MPMS): Chapter 7, Section 1, Static temperature Determination Using Mercury-in-GlassThermometers Chapter 7, Section 2, Dynamic Temperature Determination Chapter 7, Section 3, Static Temperature Det
15、ermination Using Portable ElectricThermometers Chapter 7, Section 4, Static Temperature Determination Using Fixed AutomaticTank ThermometersThis publication is primarily intended for use in the United States and is related to thestandards, specications, and procedures of the National Institute of St
16、andards and Technol-ogy (NIST). When the information provided herein is used in other countries, the specica-tions and procedures of the appropriate national standards organizations may apply. Whereappropriate, other test codes and procedures for checking pressure and electrical equipmentmay be used
17、.For the purposes of business transactions, limits on error or measurement tolerance areusually set by law, regulation, or mutual agreement between contracting parties. This publi-cation provides guidance on tolerances that are recommended for custody transfer applica-tions, and also describes metho
18、ds by which acceptable approaches to any desired accuracycan be achieved.API publications may be used by anyone desiring to do so. Every effort has been made bythe Institute to assure the accuracy and reliability of the data contained in them; however, theInstitute makes no representation, warranty,
19、 or guarantee in connection with this publicationand hereby expressly disclaims any liability or responsibility for loss or damage resultingfrom its use or for the violation of any federal, state, or municipal regulation with which thispublication may conict.Suggested revisions are invited and shoul
20、d be submitted to the standardization manager,American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005.iiiCONTENTSPage0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 SCOPE AND SAFETY CONSIDERATIONS . . . .
21、 . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22、. . . . . . . 12 REFERENCES AND RELATED PUBLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 13 DEFINITION OF TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 SIGNIFICANCE AND USE. . . . . . . . . . . . . . . . . . . . . . . . . . . .
23、 . . . . . . . . . . . . . . . . . . 35 EQUIPMENT AND APPARATUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35.1 Fixed Automatic Tank Thermometers (ATTs) . . . . . . . . . . . . . . . . . . . . . . . . . . . 35.2 Portable Electronic Thermometers (PETs) . . . . . .
24、 . . . . . . . . . . . . . . . . . . . . . . . . 85.3 Glass Thermometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95.4 Electronic Temperature Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125.5 Thermowells. . .
25、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135.6 Data Collection, Data Transmission, and Receiving Equipment . . . . . . . . . . . . 136 STATIC TEMPERATURE DETERMINATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156.1 Ambient Tem
26、perature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166.2 Timing of Temperature Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166.3 Fixed Automatic Tank Thermometers . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27、 . . . . . 166.4 Portable Electronic Thermometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176.5 Mercury-in-Glass Thermometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 DYNAMIC TEMPERATURE DETERMINATION. . . . . . . . . . . . . . . . . .
28、 . . . . . . . . 217.1 Temperature Sensor Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217.2 Temperature Discrimination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 CALIBRATION VERIFICATION, AND INSPECTION. . . . . . . .
29、 . . . . . . . . . . . . . . 238.1 Fixed Automatic Tank Thermometers (ATTs) . . . . . . . . . . . . . . . . . . . . . . . . . . 238.2 Portable Electronic Thermometers (PETs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278.3 Glass and Mercury-in-Glass Thermometer Verication . . . . . .
30、. . . . . . . . . . . . . 278.4 Dynamic Verication and Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289 FACTORS THAT AFFECT TEMPERATURE MEASUREMENT UNCERTAINTY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31、289.1 Fixed Automatic Tank Thermometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289.2 Dynamic Temperature Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29vPageAPPENDIX A EMERGENT-STEM CORRECTION FOR LIQUID-IN-GLASS THERMOMETERS . . . . . .
32、 . . . . . . . . . . . . . . . . . 31APPENDIX B LOCAL DIRECT-READING THERMOMETERS . . . . . . . . . . . . . . . . 33APPENDIX C ACCURACY LIMITATIONS OF TANK TEMPERATUREMEASUREMENTS ONBOARD MARINE VESSELS. . . . . . . . . . . . . 35APPENDIX D TEST PROCEDURE FOR DETERMINING IMMERSION TIMES OF MERCURY-I
33、N-GLASS TANK THERMOMETERSAND THEIR ASSEMBLIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37Figures1 Example of Multiple Spot Temperature Element Installation . . . . . . . . . . . . . . . . . 52 Example of Variable Length ATT Temperature Element Installation . . . . . . . . .
34、. . 63 Example of Thermocouple System Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 Types of Glass Thermometers and Their Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Typical Cup-Case Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35、. . . . . . . . . . . . 116 Typical Armored-Case Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Typical Angle-Stem Thermometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Tables1 Elevation of Temperature Elements . . . . . . .
36、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Normal Lengths of Elements of a Typical Variable Length RTD Temperature Element System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Portable Electronic Thermometer Specications . . . . . . . . .
37、 . . . . . . . . . . . . . . . . . . 84 Tank Thermometers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Minimum Number of Temperature Measurements for Various Depths of Hydrocarbon Liquid in Storage, Lease, Ship and Barge Tanks. . . . . . . . .
38、. . . . 156 Comparison of Recommended Immersion Times for PETs andWoodback Cup-Case Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 Thermometer Assemblies and Temperature Levels for Tanks andCargo Carriers . . . . . . . . . . . . . . . . . . . . . . . . . .
39、 . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 Maximum Deviation Limits: Temperature Device Versus ReferenceThermometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28B-1 Tank Appurtenances for Temperature Measurement . . . .
40、 . . . . . . . . . . . . . . . . . . . 33D-1 Suggested Bath Temperatures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37D-2 Time Intervals for Reading Thermometers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371Chapter 7Temperature Determination0
41、IntroductionThe purpose of this standard is to describe methods andpractices that may be used to obtain accurate measurementsof temperature of petroleum and petroleum products in pipe-lines, storage tanks, gathering tanks, ships, barges, tank cars,pipe provers, tank provers and test measures under b
42、oth staticand dynamic conditions using electronic temperature measur-ing devices or mercury-in-glass thermometers.1 Scope and Safety Considerations1.1 SCOPEThis chapter describes the methods, equipment, and proce-dures for determining the temperature of petroleum andpetroleum products under both sta
43、tic and dynamic conditions.This chapter discusses temperature measurement require-ments in general for custody transfer, inventory control, andmarine measurements. The actual method and equipmentselected for temperature determination are left to the agree-ment of the parties involved.Temperatures of
44、 hydrocarbon liquids under static condi-tions can be determined by measuring the temperature of theliquid at specic locations. Examples of static vessels arestorage tanks, eld gathering tanks, ships, barges, tank cars,tank provers, and test measures. Three methods are availablefor determining averag
45、e static tank temperatures for custodytransfer. Automatic method using xed electronic temperaturesensors. Manual method using portable electronic thermome-ters. Manual method using mercury-in-glass thermometers.The automatic method covers the determination of temper-ature using xed automatic tank te
46、mperature (ATT) systemsfor hydrocarbons having a Reid Vapor Pressure at or below101 kPa (15 pounds per square inch absolute). ATT systemsinclude precision temperature sensors, eld-mounted trans-mitters for electronic signal transmission, and readout equip-ment.The manual method covers: nonpressurize
47、d tanks and marine vessels blanketed tanks and marine vessels tanks and marine vessels that have been made inert andare under pressures of less than 21 kPa (3 pounds persquare inch gauge)It does not cover hydrocarbons under pressures in excess of21 kPa (3 pounds per square inch gauge) or cryogenic t
48、em-perature measurement, unless the tank is equipped with athermowell.Temperatures of hydrocarbon liquids under dynamic con-ditions can be determined by measuring the temperature ofthe liquid as it is owing through a pipe. Dynamic tempera-ture can be determined automatically or manually using elec-t
49、ronic temperature devices or mercury-in-glass thermometers.The use of thermowells may be required in dynamic measure-ment to isolate the liquid material from the temperature sen-sor.The requirements of this chapter are based on practices forcrude oils and petroleum products covered by API MPMSChapter 11.1 (ASTM D 1250). Requirements in this chaptermay be used for other uids and other applications. However,other applications may require different performance andinstallation specications.1.2 SAFETYSafety considerations must be included in all equipments