ASTM E207-21 PDF
Standard Test Method for Thermal EMF Test of Single Thermoelement Materials by Comparison With Reference Thermoelement of Similar EMF-Temperature Properties
Standard Test Method for Thermal EMF Test of Single Thermoelement Materials by Comparison With Reference Thermoelement of Similar EMF-Temperature Properties
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 7
- Дата публикации:
- 1 мая 2021 г.
- Издание:
- E207
- ICS:
- 17.200.20
SIGNIFICANCE AND USE 5.1 This test method is designed to calibrate a thermoelement at one or more test temperatures. The data obtained are sometimes referred to as initial values of emf because the time at the test temperature is limited. 5.2 This test method is employed mainly by providers of spools or coils of wire or strips of thermoelectric material. Generally more than one specimen at a time is tested, and the resultant emfs of individual thermoelements are used to match to companion thermoelements for use as thermocouples or in extension wiring. 5.3 The emf of a thermocouple comprised of two different thermoelements as tested with this test method may be determined by algebraically subtracting the emf of the negative thermoelement from the emf of the positive thermoelement at a particular temperature. The emf of a thermocouple may also be determined by the test described in Test Method E220, but Test Method E220 does not take into account the values of the emf of the individual thermoelements relative to Pt-67. 5.4 This test method is normally used for the calibration of thermocouple materials during their production or distribution, not for the accurate determination of the properties of a used thermocouple. If the test samples were subjected to previous use, the test results may not reflect the same emf as the thermocouple did while in service. For example, inhomogeneities may have been induced in the wires because of a chemical or metallurgical reaction while in service. Since emf is developed in the thermal gradient, and it is unlikely that the temperature profile along the wire under testing conditions will be the same as it was while in service, the test results may be misleading. 5.5 The test results are suitable for specification acceptance, manufacturing control, design, or research and development purposes. SCOPE 1.1 This test method covers a test for determining the thermoelectric electromotive force (emf) of a thermoelement versus National Instruments of Standards and Technology (NIST) platinum 67 (Pt-67) by means of measuring the difference between the emf of the test thermoelement and the emf of a reference thermoelement (previously referred to as a secondary standard), which has a known relationship to NIST Pt-67. 1.2 This test method is applicable to new thermocouple materials over the temperature ranges normally associated with thermocouples and their extension wires. The table on Suggested Upper Temperature Limits for Protected Thermocouples in Specification E230/E230M lists the ranges associated with the letter-designated types of thermocouples. ASTM MNL122 lists the temperature range of extension circuit materials. 1.3 This test method is not applicable to stability testing or inhomogeneity testing. 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Abstract
Overview
ASTM E207-21: Standard Test Method for Thermal EMF Test of Single Thermoelement Materials by Comparison With Reference Thermoelement of Similar EMF-Temperature Properties provides a reliable procedure for calibrating thermoelement materials used in thermocouple manufacturing. This standard, issued by ASTM International, focuses on determining the thermoelectric electromotive force (emf) of a test thermoelement compared to a reference thermoelement with a known relationship to NIST platinum 67 (Pt-67). The resulting data assist manufacturers and suppliers of thermoelectric wires or strips in ensuring quality, consistency, and traceability in temperature measurement applications.
Key Topics
-
Calibration of New Thermoelement Materials: The standard is primarily employed to calibrate new, unused thermocouple materials at one or more specified test temperatures, establishing initial emf values used for subsequent matching and assembly.
-
Comparison With Reference Thermoelement: The emf of the test thermoelement is measured against a reference thermoelement already calibrated relative to NIST Pt-67. This enables high-accuracy and traceable results.
-
Application Scope: Applicable to new thermocouple and extension wire materials across the standard temperature ranges defined in ASTM E230/E230M and relevant manuals. The method is not intended for in-service or used thermocouples due to possible material inhomogeneities from previous exposure.
-
Testing Strategy: Multiple specimens, typically from both ends of a spool, coil, or strip, are tested together. The measured emfs are used to match materials for paired applications or for use in extension wires.
-
Calculation Approach: Results are calculated based on measured emf values at controlled test and reference temperatures. The emf of a complete thermocouple is determined by subtracting the negative element’s emf from the positive’s at the same temperature, allowing for accurate thermoelectric property determination.
-
Quality and Traceability: The method mandates the use of certified reference materials and traceability to national standards, ensuring data reliability for manufacturing control, specification acceptance, and research.
Applications
-
Manufacturing Control: Enables manufacturers to assess and balance batches of thermoelement material, verifying conformity with technical specifications and ensuring product consistency in thermocouple performance.
-
Specification Acceptance & Matching: Used during production or distribution to confirm materials meet specified emf values at required temperatures, facilitating precise matching of thermoelements for assembly into thermocouples or extension wires.
-
Design and R&D: Provides essential emf data for design engineering, materials development, and research in temperature measurement technologies.
-
Certification: Offers a standardized basis for issuing certificates of conformance, indicating that materials have been tested in compliance with ASTM E207, with traceable data to NIST standards.
Related Standards
- ASTM E220 - Standard Test Method for Calibration of Thermocouples by Comparison Techniques
- ASTM E230/E230M - Specification for Temperature-Electromotive Force Tables for Standardized Thermocouples
- ASTM E344 - Terminology Relating to Thermometry and Hydrometry
- ASTM E563 - Practice for Preparation and Use of an Ice-Point Bath as a Reference Temperature
- ASTM MNL12 - Manual on the Use of Thermocouples in Temperature Measurement
These related standards offer additional guidance for thermocouple calibration, terminology, reference temperature maintenance, and temperature-emf relationships, supporting comprehensive control and quality in the thermoelectric measurement industry.
By following ASTM E207-21, organizations standardize the calibration and quality confirmation of thermoelement materials, contributing to the dependability and global traceability of temperature measurement systems. Keywords: thermoelement calibration, thermal emf, reference thermoelement, NIST Pt-67, thermocouple manufacturing, ASTM E207, traceability, temperature measurement standards.
Технические детали
- Технический комитет
- E20 - Temperature Measurement
- SKU
- ASTM E207-21
Похожие стандарты
Другие стандарты ASTM
ASTM-TPT-47
Phase I & Phase II Environmental Site Assessment Processes
Phase I & Phase II Environmental Site Assessment Processes
ASTM-TPT-8
Phase I Environmental Site Assessment Practices For Commercial Real Estate: Phase I Site Assessment & Transac…
ASTM-TPT-1137
ASTM D975 Standard Specification for Diesel Fuel
ASTM D975 Standard Specification for Diesel Fuel
ASTM-TPT-1202
ASTM D8421 Standard Test Method for Determination of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous Ma…
ASTM D8421 Standard Test Method -- eLearning Course
ASTM-TPT-691
Microaprendizagem para D4057: Amostragem de ponto (PT)
D4057 Microlearning: Spot Sampling Portuguese
ASTM-TPT-1091
Metodo de prueba estandar D4052 de ASTM -- Curso de aprendizaje electrónico (ES)
Modulo eLearning para ASTM D4052 en espanol
ASTM ACEM20180086
Using Neutron Radiography to Quantify the Settlement of Fresh Concrete
Specifications have been implemented for concrete bridge decks in North America that restrict the use of higher slump concrete mixtures primarily because of concerns about differential settlement and…
ASTM ACEM20180041
Experimental Study of Competing Failure of Reinforced Concrete Based on the Weibull Distribution
To predict the failure lifetime of reinforced concrete, a current accelerating corrosion test was performed on concrete by simulating the environment in an area with saline soil. To study the concret…