1、Designation: E879 12Standard Specification forThermistor Sensors for General Purpose and LaboratoryTemperature Measurements1This standard is issued under the fixed designation E879; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he 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 specification covers the general requirements forNegative Temperature Coefficient (NTC) thermistor-typ
3、e sen-sors intended to be used for laboratory temperature measure-ments or control, or both, within the range from 10 to 105C.1.2 This specification also covers the detailed requirementsfor ASTM designated sensors.1.3 This specification also covers the requirements forgeneral purpose, Negative Tempe
4、rature Coefficient (NTC)thermistor-type sensors intended for use with Digital ContactThermometers (also known as Digital Thermometers) withinthe range from 50 to +150C.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of
5、 the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E344 Terminology Relating to Thermometry and Hydrom-etryE563 Practice for Preparation and Use of an Ice-
6、Point Bathas a Reference TemperatureF29 Specification for Dumet Wire for Glass-to-Metal SealApplications3. Terminology3.1 DefinitionsThe definitions given in TerminologyE344 shall apply to this specification.3.2 Definitions of Terms Specific to This Standard:3.2.1 dissipation constant, d, nthe ratio
7、 of the change inenergy dissipated per unit time (power) in a thermistor,DP = P2 P1, to the resultant temperature change of thethermistor, DT = T2 T1.d5DPDT(1)The dimensions of the dissipation constant are W/K.For this specification, T1is in the range from 20 to 38C andDT = 10C.3.2.2 dumet, nround,
8、copper-coated 42 % nickel-ironwire intended primarily for sealing to soft glass.Also known asCuNiFe in some communities.3.2.3 insulation resistance, dc, nthe resistance at a speci-fied direct-current voltage between the insulated leads of athermistor sensor and the metallic enclosure of the sensor,
9、ifsuch an enclosure is present, or else between the sensor leadsand a conductive medium in which the sensor is immersed.3.2.4 qualification test, na series of tests conducted by theprocuring agency or an agent thereof to determine confor-mance of thermistor sensors to the requirements of a specifi-c
10、ation, normally for the development of a qualified productslist under the specification.3.2.5 response time, nthe time required for a sensor tochange a specified percentage of the total difference betweenits initial and final temperatures as determined from zero-power resistances when the sensor is
11、subjected to a stepfunction change in temperature.1This specification is under the jurisdiction of ASTM Committee E20 onTemperature Measurement and is the direct responsibility of Subcommittee E20.03on Resistance Thermometers.Current edition approved May 1, 2012. Published June 2012. Originallyappro
12、ved in 1982. Last previous edition approved in 2007 as E879 01 (2007).DOI: 10.1520/E0879-01R07.2For 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 Documen
13、t Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.6 time constant, nthe 63.2 % response time of asensor that exhibits a single-exponential response.3.2.7 zero-power resistance, nthe dc resistance o
14、f a de-vice, at a specified temperature, calculated for zero-power.3.2.7.1 DiscussionAccurate zero-power resistance is ob-tained by extrapolating to zero-power the resistance valuesobtained from measurements at three or more levels of powerwith the sensor immersed in a constant temperature medium.Fo
15、r the purpose of this specification, this is obtained frommeasurements at a single power level adjusted such that thepower is not greater than one-fifth the product of the dissipa-tion constant specified in Table 1 (see 3.2.1 and 7.3) and theappropriate tolerance requirement of Table 2. When makings
16、tability measurements, the power shall be kept constant.4. Classification4.1 Thermistor sensors covered by this specification shall beclassified with a type designation code that includes theASTMdetailed specification number followed by a descriptive code.See Fig. 1.4.2 ASTM Specification NumberThe
17、ASTM specificationnumber specifies uniquely the design and construction of thesensor including the type designation if more than one typeappears in the same specification.4.2.1 Type DesignationThe type designation shall be aletter symbol to indicate the design and construction of thethermistor senso
18、r.4.2.1.1 Type SSilicone rubber-coated glass probe withtinned Dumet extension leads (see Fig. 2).4.2.1.2 Type EEpoxy-coated glass probe with silver-plated copper extension leads (see Fig. 3).4.2.1.3 Type GGeneral purpose four wire sensor in stain-less steel housing (see Fig. 4).4.2.1.4 Type HGeneral
19、 purpose two-wire sensor in stain-less steel housing (see Fig. 5).4.2.1.5 Type VInterchangeable sensor enclosed in 1.2-mmvinyl tube (see Fig. 6).4.2.1.6 Type WNon-interchangeable sensor enclosed in0.9-mm vinyl tube (see Fig. 7).4.3 Operating Temperature RangeThe operating tempera-ture range shall be
20、 designated by a letter symbol (see Table 3).4.4 Accuracy ClassThe accuracy class shall be designatedby a single-digit number (see Table 2).4.5 Calibration TypeThe type of calibration required foreach unit shall be designated by a letter symbol. The letter Ishall be used to denote units that are int
21、erchangeable withrespect to a single resistance-temperature relationship. Theletter N shall be used to denote non-interchangeable units forwhich resistance-temperature information must be furnishedfor each unit. For Calibration Type N sensors, serial numberidentification must be provided.5. Requirem
22、ents5.1 SpecificationsSensors shall comply with the generalrequirements specified herein as well as with the applicabledetailed specifications of Table 1. In the event of conflictbetween this requirement paragraph and the detailed specifi-cation of Table 1, Figs. 2-7 the latter shall govern.5.2 Zero
23、-Power Resistance versus TemperatureRelationshipThe zero-power resistance versus temperaturerelationship shall be presented in a form such that anytemperature within the specified operating temperature rangecan be obtained from that relationship and have an uncertaintyno greater than one-tenth the s
24、pecified tolerance in Table 2.When tested in accordance with 7.2, the zero-power resistanceversus temperature relationship for interchangeable parts shallcomply to within the tolerance specified in Table 2. Themanufacturer of the sensor shall, for non-interchangeable parts,supply this relationship w
25、ith each part shipped.5.2.1 AccuracyThe resistance-temperature relationship,provided in Table 1, or with the sensor, or both, shall not differfrom that obtained from measurements made in accordancewith 7.2 by more than the tolerances specified inTable 2 for theapplicable intervals specified in Table
26、 1.5.3 Thermal Requirements:5.3.1 Dissipation ConstantWhen tested in accordancewith 7.3, the dissipation constant shall be as specified in thedetailed specification.5.3.2 Response TimeWhen tested in accordance with 7.4,the response time or time constant, or both, shall be as specifiedin the detailed
27、 specification.5.4 Environmental Requirements:5.4.1 Operating Temperature RangeThe operating tem-perature range shall be as specified in the type designation code(see 4.1 and 4.3).5.4.2 Storage Temperature RangeSensors shall be ca-pable of meeting all requirements specified herein as well asthose li
28、sted in the applicable detailed specification after storageat any temperature (or combination thereof) in the rangefrom 40 to 60C for a period of 1 year.5.4.3 Humidity RequirementSensors shall be capable ofbeing operated or stored at relative humidity from 0 to 95 %without condensation.5.5 Stability
29、:5.5.1 Short-Term Stability (10 days)When tested in accor-dance with 7.5.1, the equivalent temperature shift shall be nogreater than 10 % of the tolerance shown in Table 2 for theaccuracy class specified.5.5.2 Long-Term Stability (120 days)When tested in ac-cordance with 7.5.2, the equivalent temper
30、ature shift shall beno greater than 25 % of the tolerance shown in Table 2 for theaccuracy class specified.5.6 Low-Temperature StorageWhen tested in accordancewith 7.6, there shall be no evidence of mechanical damage andthe sensor shall comply with the accuracy requirements of 5.2.5.7 Thermal ShockW
31、hen tested in accordance with 7.7,there shall be no evidence of mechanical damage and thesensor shall comply with the accuracy requirements of 5.2.5.8 Insulation Resistance:5.8.1 Dry TestThis requirement shall apply to sensors thathave exposed metallic surfaces, but are not designed forimmersion in
32、conductive fluids. When tested in accordancewith 7.8.1, there shall be no evidence of mechanical damageand the insulation resistance shall be sufficiently high that itsshunting effect will not prevent the unit from complying withE879 122TABLE 1 Specification for ASTM Clinical Laboratory Thermistor S
33、ensorsASTM No. E879 S B1N E879 E B1N E879 S B2N E879 E B2NDescription Silicone Rubber Coated GlassProbeEpoxy Coated Glass Probe Silicone Rubber Coated GlassProbeEpoxy Coated Glass ProbeMajor Application General Purpose ClinicalLaboratory TemperatureMeasurementGeneral Purpose ClinicalLaboratory Tempe
34、ratureMeasurementGeneral Purpose ClinicalLaboratory TemperatureMeasurementGeneral Purpose ClinicalLaboratory TemperatureMeasurementOperating Temperature Range 10 to 60C 10 to 60C 10 to 60C 10 to 60CAccuracy Class 1 (60.01C) 1 (60.01C) 2 (60.02C) 2 (60.02C)Temperatures for Accuracy Class 10 to 60C 10
35、 to 60C 10 to 60C 10 to 60CAccuracies for other TemperaturesWithin Specified TemperatureRangeCalibration Type Non-interchangeable Non-interchangeable Non-interchangeable Non-interchangeableNominal R-T CharacteristicR = expA0+ A1/T + A2/T2+A3/T3 (T in kelvins)T( C) = a0+a1LnR +a2(LnR)2+a3(LnR)31 273.
36、15A04.4495078 4.4495078 4.4495078 4.4495078A13614.7764 3614.7764 3614.7764 3614.7764A288190.906 88190.906 88190.906 88190.906A322328247 22328247 22328247 22328247a00.11766716 3 1020.11766716 3 1020.11766716 3 1020.11766716 3 102a10.28173082 3 1030.28173082 3 1030.28173082 3 1030.28173082 3 103a20.23
37、285292 3 1050.23285292 3 1050.23285292 3 1050.23285292 3 105a30.24131652 3 1060.24131652 3 1060.24131652 3 1060.24131652 3 106Type of Immersion Fluid water, air water, oil, air water, air water, oil, airNominal R0at 25C 2.5 kV 2.5 kV 2.5kV 2.5 kVDissipation Constant 3.5 6 0.9 mW/K 5.0 6 1.2 mW/K 3.5
38、6 0.9 mW/K 5.0 6 1.2 mW/K63.2 % Response Time 0.55 6 0.16 s 0.45 6 0.11 s 0.55 6 0.16 s 0.45 6 0.11 sRatio of 95 % to 63.2 % ResponseTimes2.5 6 0.6 2.1 6 0.5 2.5 6 0.6 2.1 6 0.5Design and Construction Fig. 2 Fig. 3 Fig. 2 Fig. 3ASTM No. E879 S A2N E879 E A2N E879 G B1N E879 H B1NDescription Silicone
39、 Rubber Coated GlassProbeEpoxy Coated Glass Probe5kV -4-WireNon-interchangeable Sensorin S.S. Housing5kV -2-WireNon-interchangeableSensorin S.S. HousingMajor Application General Purpose ClinicalLaboratory TemperatureMeasurementGeneral Purpose ClinicalLaboratory TemperatureMeasurementGeneral Purpose
40、ClinicalLaboratory TemperatureMeasurementGeneral Purpose ClinicalLaboratory TemperatureMeasurementOperating Temperature Range 10 to 105C 10 to 105C 10 to 60C 10 to 60CAccuracy Class 2 (60.02C) 2 (60.02C) 1 (60.01C) 1 (60.01C)Temperatures for Accuracy Class 10 to 105C 10 to 105C 10 to 60C 10 to 60CAc
41、curacies for other TemperaturesWithin Specified TemperatureRangeCalibration Type Non-interchangeable Non-interchangeable Non-interchangeable Non-interchangeableNominal R-T CharacteristicR = expA0+ A1/T + A2/T2+A3/T3T( C) = a0+a1LnR +a2(LnR)2+a3(LnR)31 273.15A04.3332974 4.3332947 3.7563605 3.7563605A
42、14440.1603 4440.1603 3614.7764 3614.7764A2104525.78 104525.78 88190.906 88190.906A34581329.78 4581329.78 22328247 22328247a00.98667965 3 1030.98667965 3 1030.98019160 3 1030.98019160 3 103a10.24329879 3 1030.24329879 3 1030.28530667 3 1030.28530667 3 103a20.59584872 3 1060.59584872 3 1060.28303328 3
43、 1050.28303328 3 105a30.97166167 3 1070.97166167 3 1070.24131652 3 1060.24131652 3 106Type of Immersion Fluid water, air water, air all fluids compatible with Type304 S.S.all fluids compatible withType 304 S.S.R0at 25C 10kV 10 kV 5 kV 5 kVDissipation Constant 3.5 6 0.9 mW/K 5.0 6 1.2 mW/K 4.86 1.2 m
44、W/K 4.8 6 1.2 mW/K63.2 % Response Time 0.55 6 0.16 s 0.45 6 0.11 s 4.5 6 1.1 s 4.5 6 1.1 sRatio of 95 % to 63.2 % ResponseTimes2.5 6 0.6 2.1 6 0.5 2.6 6 0.3 2.6 6 0.3Design and Construction Fig. 2 Fig. 3 Fig. 4 Fig. 5E879 123TABLE 1 (continued)ASTM No. E879 G B1N E879 H B1N E879 G A2N E879 H A2NDesc
45、ription 10 kV 4-Wire Non-interchangeable Sensor inS.S. Housing10 kV 2-Wire Non-interchangeable Sensor inS.S. Housing10 kV 4-Wire Non-interchangeable Sensor inS.S. Housing10 kV 2-Wire Non-interchangeable Sensor inS.S. HousingMajor Application General Purpose ClinicalLaboratory TemperatureMeasurementG
46、eneral Purpose ClinicalLaboratory TemperatureMeasurementGeneral Purpose ClinicalLaboratory TemperatureMeasurementGeneral Purpose ClinicalLaboratory TemperatureMeasurementOperating Temperature Range 10 to 60C 10 to 60C 10 to 105C 10 to 105CAccuracy Class 1 (60.01C) 1 (60.01C) 2 (60.02C) 2 (60.02C)Tem
47、peratures for AccuracyClass10 to 60C 10 to 60C 10 to 105C 10 to 105CAccuracies for otherTemperaturesWithin Specified TemperatureRangeCalibration Type Non-interchangeable Non-interchangeable Non-interchangeable Non-interchangeableNominal R-T CharacteristicR = expA0+ A1/T + A2/T2+A3/T3T(C) = a0+a1LnR
48、+a2(LnR)2+a3(LnR)31 273.15A03.5684919 3.5684919 3.7191520 3.7191520A13907.7065 3907.7065 4045.1666 4045.1666A233480.382 33480.382 8181.7100 -8181.7100A318666997 18666997 14472122 14472122a00.86972495 3 1030.86972495 3 1030.89898144 3 1030.89898144 3 103a10.27135335 3 1030.27135335 3 1030.26152805 3
49、1030.26152805 3 103a20.20689100 3 1050.20689100 3 1050.97537969 3 1060.97537969 3 106a30.20547429 3 1060.20547429 3 1060.16613292 3 1060.16613292 3 106Type of Immersion Fluid all fluids compatible with Type304 S.S.all fluids compatible with Type304 S.S.all fluids compatible with Type304 S.S.all fluids compatible with Type304 S.S.Nominal R0at 25 C 10 kV 10kV 10 kV 10 kVDi
