1、Designation: E344 16Terminology Relating toThermometry and Hydrometry1This standard is issued under the fixed designation E344; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indi
2、cates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This terminology is a compilation of definitions of termsused by ASTM Committee E20 on Temperature Measurement.1.2 Terms with definitions generally applicable to
3、 the fieldsof thermometry and hydrometry are listed in 3.1.1.3 Terms with definitions applicable only to the indicatedstandards in which they appear are listed in 3.2.1.4 Information about the International Temperature Scaleof 1990 is given in Appendix X1.2. Referenced Documents2.1 ASTM Standards:2E
4、1 Specification for ASTM Liquid-in-Glass ThermometersE77 Test Method for Inspection and Verification of Ther-mometersE100 Specification for ASTM HydrometersE126 Test Method for Inspection, Calibration, and Verifica-tion of ASTM HydrometersE207 Test Method for Thermal EMF Test of Single Thermo-elemen
5、t Materials by Comparison with a Reference Ther-moelement of Similar EMF-Temperature PropertiesE220 Test Method for Calibration of Thermocouples ByComparison TechniquesE230 Specification and Temperature-Electromotive Force(EMF) Tables for Standardized ThermocouplesE452 Test Method for Calibration of
6、 Refractory Metal Ther-mocouples Using a Radiation ThermometerE574 Specification for Duplex, Base Metal ThermocoupleWire With Glass Fiber or Silica Fiber InsulationE585/E585M Specification for Compacted Mineral-Insulated, Metal-Sheathed, Base Metal ThermocoupleCableE601 Guide for Measuring Electromo
7、tive Force (emf) Sta-bility of Base-Metal Thermoelement Materials with Timein AirE608/E608M Specification for Mineral-Insulated, Metal-Sheathed Base Metal ThermocouplesE644 Test Methods for Testing Industrial Resistance Ther-mometersE667 Specification for Mercury-in-Glass, Maximum Self-Registering C
8、linical ThermometersE696 Specification for Tungsten-Rhenium Alloy Thermo-couple WireE710 Test Method for Comparing EMF Stabilities of Base-Metal Thermoelements in Air Using Dual, Simultaneous,Thermal-EMF Indicators (Withdrawn 2006)3E780 Test Method for Measuring the Insulation Resistanceof Mineral-I
9、nsulated, Metal-Sheathed Thermocouples andThermocouple Cable at Room TemperatureE825 Specification for Phase Change-Type Disposable Fe-ver Thermometer for Intermittent Determination of Hu-man TemperatureE839 Test Methods for Sheathed Thermocouples andSheathed Thermocouple CableE879 Specification for
10、 Thermistor Sensors for General Pur-pose and Laboratory Temperature MeasurementsE1061 Specification for Direct-Reading Liquid Crystal Fore-head ThermometersE1104 Specification for Clinical Thermometer Probe Coversand SheathsE1112 Specification for Electronic Thermometer for Inter-mittent Determinati
11、on of Patient TemperatureE1129/E1129M Specification for Thermocouple ConnectorsE1137/E1137M Specification for Industrial Platinum Resis-tance ThermometersE1159 Specification for Thermocouple Materials, Platinum-Rhodium Alloys, and PlatinumE1256 Test Methods for Radiation Thermometers (SingleWaveband
12、 Type)E1299 Specification for Reusable Phase-Change-Type FeverThermometer for Intermittent Determination of HumanTemperatureE1350 Guide for Testing Sheathed Thermocouples, Thermo-couples Assemblies, and Connecting Wires Prior to, and1This terminology is under the jurisdiction of ASTM Committee E20 o
13、nTemperature Measurement and is the direct responsibility of Subcommittee E20.91on Editorial and Terminology.Current edition approved Nov. 1, 2016. Published December 2016. Originallyapproved in 1968. Last previous edition approved in 2013 as E344 13. DOI:10.1520/E0344-16.2For referenced ASTM standa
14、rds, 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 ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copy
15、right ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1After Installation or ServiceE1502 Guide for Use of Fixed-Point Cells for ReferenceTemperaturesE1594 Guide for Expression of TemperatureE1684 Specification for Miniature Thermocouple Connec-
16、torsE1750 Guide for Use of Water Triple Point CellsE1751 Guide for Temperature Electromotive Force (EMF)Tables for Non-Letter Designated Thermocouple Combi-nations (Withdrawn 2009)3E1965 Specification for Infrared Thermometers for Intermit-tent Determination of Patient TemperatureE2181/E2181M Specif
17、ication for Compacted Mineral-Insulated, Metal-Sheathed, Noble Metal Thermocouplesand Thermocouple CableE2251 Specification for Liquid-in-Glass ASTM Thermom-eters with Low-Hazard Precision LiquidsE2593 Guide for Accuracy Verification of Industrial Plati-num Resistance Thermometers2.2 Other Standards
18、, Supplementary Vocabularies, andSources:4International Vocabulary of Basic and General Terms inMetrology (VIM) 1993Guide to the Expression of Uncertainty in Measurement(GUM) 1995IEC 61298-1 Process Measurement and Control DevicesGeneral Methods and Procedures for EvaluatingPerformance- Part 1: Gene
19、ral Considerations53. Terminology3.1 Definitions:accuracy, nof a temperature measurement, closeness ofagreement between the result of a temperature measurementand a true value of the temperature.DISCUSSIONAccuracy is a qualitative concept.base metal thermocouple, nthermocouple whose thermo-elements
20、are composed primarily of base metals and theiralloys. (See also noble metal thermocouple; refractorymetal thermocouple.)DISCUSSIONBase metals used in thermoelements include nickel,iron, chromium, copper, aluminum. Letter-designated types E, J, K, T,and N are considered base metal thermocouples.bias
21、, nthe scatter between the mean values of subsets of data,from each other or from the accepted value.blackbody, nthe perfect or ideal source of thermal radiantpower having a spectral distribution described by the Planckequation.DISCUSSIONThe term blackbody is often used to describe a furnaceor other
22、 source of radiant power which approximates the ideal.bulb, nof a liquid-in-glass thermometer, reservoir for thethermometric liquid.calibration, n of a thermometer or thermometric system, theset of operations that establish, under specified conditions,the relationship between the values of a thermom
23、etricquantity indicated by a thermometer or thermometric systemand the corresponding values of temperature realized bystandards.DISCUSSION(1) The result of a calibration permits either theassignment of values of temperature to indicated values of thermomet-ric quantity or determination of correction
24、s with respect to indications.(2)Acalibration may also determine other metrological properties suchas the effect of influence quantities. (3) The result of a calibration maybe communicated in a document such as a calibration certificate or acalibration report. (4) The term calibration has also been
25、used to referto the result of the operations, to representations of the result, and to theactual relationship between values of the thermometric quantity andtemperature.calibration point, na specific value, established by areference, at which the indication or output of a measuringdevice is determin
26、ed.Celsius, adjpertaining to or denoting something related tothe expression of temperature in degrees Celsius.DISCUSSIONFor example, “A Celsius thermometer has a scalemarked in degrees Celsius.”center wavelength, na wavelength, usually near the middleof the band of radiant power over which a radiati
27、onthermometer responds, that is used to characterize its per-formance.DISCUSSIONThe value of the center wavelength is usually specifiedby the manufacturer of the instrument.clinical thermometer, nthermometer of any type designed tomeasure human body temperature.DISCUSSIONSome clinical thermometers m
28、ay be designed to mea-sure the body temperature of animals.coaxial thermocouplea thermocouple consisting of a ther-moelement in wire form within a thermoelement in tubeform with the wire being electrically insulated from the tubeexcept at the measuring pensating extension wires, nthose extension wir
29、esfabricated from materials basically different in compositionfrom the thermocouple.DISCUSSIONThey have similar thermoelectric properties and withina stated temperature range effectively transfer the reference junction tothe other end of the plete immersion thermometer, na liquid-in-glass ther-momet
30、er designed to indicate temperatures correctly whenthe entire thermometer is exposed to the temperature beingmeasured. (Compare total immersion thermometer andpartial immersion thermometer.)connection head, na housing enclosing a terminal block foran electrical temperature-sensing device and usually
31、 pro-vided with threaded openings for attachment to a protectingtube and for attachment of conduit.defining fixed point, nthermometric fixed point of anidealized system, to which a numerical value has beenassigned, used in defining a temperature scale.4Available from International Organization for S
32、tandardization (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.5Available from International Electrotechnical Commission (IEC), 3 rue deVaremb, Case postale 131, CH-1211, Geneva 20, Switzerland, http:/www.iec.ch.E344 162degree Celsius, C, nderived u
33、nit of temperature in theInternational System of Units (SI). (See kelvin.)DISCUSSIONAt any temperature, an interval of one degree Celsius isthe same as an interval of one kelvin, by definition. For informationabout the relation between units and values of temperature expressed indifferent units, see
34、 Guide E1594.degree centigrade, nobsolete term. Use degree Celsius.degree Fahrenheit, F, nnon-SI unit of temperature com-monly used in the United States of America.DISCUSSIONAt any temperature, an interval of one degree Fahren-heit is the same as an interval of 5/9 kelvin (or 5/9 degree Celsius). Fo
35、rinformation about the relation between units and values of temperatureexpressed in different units, see Guide E1594.electromotive force (emf), nthe electrical potential differ-ence which produces or tends to produce an electric current.error, nof a temperature measurement, result of a tempera-ture
36、measurement minus a true value of temperature.extension wires, nthose having temperature-emf character-istics that when connected to a thermocouple effectivelytransfer the reference junction to the other end of the wires.(Compare compensating wires).Fahrenheit, adjpertaining to or denoting something
37、 relatedto the expression of temperature in degrees Fahrenheit.DISCUSSIONFor example, “A Fahrenheit thermometer has a scalemarked in degrees Fahrenheit.”fixed point, n in thermometry, reproducible temperature ofequilibrium of a system of two or more phases underspecified conditions.freezing point, n
38、fixed point of a single component system inwhich liquid and solid phases are in equilibrium at aspecified pressure, usually 101 325 Pa, and the system islosing heat slowly. (Compare melting point.)grounded junction, n A measuring junction of a thermo-couple assembly that is electrically and physical
39、ly connectedto its sheath. Also see Style G.DISCUSSIONThe term “grounded” has been historically accepted inthe field of thermometry to indicate the electrical connectivity of athermocouples measuring junction to its sheath; the term does notindicate whether or not the measuring junction is electrica
40、lly connectedto earth or circuit ground.hysteresis, nThe property of a device or instrument wherebyit gives different output values in relation to its input valuesdepending upon the directional sequence in which the inputvalues have been applied. IEC 61298-1ice point, nthermometric fixed point of ic
41、e and watersaturated with air at a pressure of 101 325 Pa.industrial platinum resistance thermometer (IPRT), narugged platinum resistance thermometer suitable for tem-perature measurements in harsh industrial environmentsover all or part of the temperature range -200 C to 650 C.DISCUSSION(1) The sen
42、sing element is made from platinum wire orfilm and packaged in a rugged housing to withstand harsh operatingconditions. The sheath material is usually stainless steel or Inconel;however, other materials may be used for special applications. (2) Theresistance-temperature relationship is usually defin
43、ed by a specifiednominal equation and interchangeability tolerances over a specifiedtemperature range. (3) IPRTs have ice-point resistance values of at least100 ohms, and are available with two-wire, three-wire or four-wireterminations. (4) IPRTs are the most rugged and lowest cost platinumresistanc
44、e thermometers.International Practical Temperature Scale (IPTS-48),nthe temperature scale adopted by the 11th GeneralConference on Weights and Measures in 1960 and replacedin 1968 by the International Practical Temperature Scale of1968.International Practical Temperature Scale of 1968 (IPTS-68), nth
45、e temperature scale adopted by the 13th GeneralConference on Weights and Measures in 1968.DISCUSSIONThe IPTS-68 was superseded in 1990 by the Interna-tional Temperature Scale of 1990.International Temperature Scale of 1990 (ITS-90), nthetemperature scale prepared in accordance with instructionsof th
46、e 18th General Conference on Weights and Measures,and adopted on January 1, 1990.kelvin, K, nbase unit of temperature in the InternationalSystem of Units (SI).liquid-in-glass thermometer, na temperature-measuring in-strument whose indications are based on the temperaturecoefficient of expansion of a
47、 liquid relative to that of itscontaining glass bulb.lower range value, nthe lowest quantity that an instrumentis adjusted to measure.maximum permissible errors, nof a thermometer or ther-mometric system, extreme values permitted by regulation orspecification of the difference between the indication
48、 of athermometer or thermometeric system and the true value oftemperature.DISCUSSIONThe term tolerance is sometimes used in ASTM stan-dards to represent this concept.maximum self-registering clinical thermometer, nclinicalthermometer designed to retain the indication of its maxi-mum measured tempera
49、ture until reset.measuring junction, nthat junction of a thermocouplewhich is subjected to the temperature to be measured.melting point, nfixed point of a single component system inwhich liquid and solid phases are in equilibrium at aspecified pressure, usually 101 325 Pa, and the system isgaining heat slowly. (Compare freezing point.)noble metal thermocouple, nthermocouple whose thermo-elements are composed primarily of noble metals and theiralloys. (See also base metal thermocouple; refractorymetal
