GB/T 25897-2020 English PDFUS$514.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 25897-2020: Residual resistance ratio measurement. Residual resistance ratio of Nb-Ti and Nb[3]Sn composite superconductors Status: Valid GB/T 25897: Historical versions
Basic dataStandard ID: GB/T 25897-2020 (GB/T25897-2020)Description (Translated English): Residual resistance ratio measurement. Residual resistance ratio of Nb-Ti and Nb[3]Sn composite superconductors Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: H21 Classification of International Standard: 17.220.20 29.050 Word Count Estimation: 27,261 Date of Issue: 2020-12-14 Date of Implementation: 2021-07-01 Older Standard (superseded by this standard): GB/T 25897-2010 Quoted Standard: IEC 60050-815 Adopted Standard: IEC 61788-4-2020, IDT Regulation (derived from): National Standard Announcement No. 28 of 2020 Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration Summary: This standard specifies the niobium-titanium (Cu), copper-nickel (Cu-Ni), copper/copper-nickel (Cu/Cu-Ni) matrix and aluminum (Al) matrix under the condition of no strain and no applied magnetic field. Nb-Ti) and Nb[3]Sn (Nb[3]Sn) composite superconductor residual resistance ratio (RRR) test method. This standard applies to the measurement of the residual resistance ratio of integrated superconductors with a residual resistance ratio of less than 350 and a cross section of less than 3 mm^2. For the Nb[2]Sn composite superconductor, the sample undergoes reaction heat treatment. GB/T 25897-2020: Residual resistance ratio measurement. Residual resistance ratio of Nb-Ti and Nb[3]Sn composite superconductors---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. (Measurement of residual resistance ratio Measurement of residual resistance ratio of niobium-titanium (Nb-Ti) and niobium tin (Nb3Sn) composite superconductors) ICS 17:220:20,29:050 H21 National Standards of People's Republic of China Replace GB/T 25897-2010 Residual resistance ratio measurement niobium-titanium (Nb-Ti) And niobium tin (Nb3Sn) composite superconductor Residual resistance ratio measurement (IEC 61788-4:2020,Superconductivity-Part 4: Residualresistance Released on 2020-12-14 Implemented on 2021-07-01 State Administration for Market Regulation Issued by the National Standardization Management Committee Table of contentsForeword Ⅰ Introduction Ⅱ 1 Scope 1 2 Normative references 1 3 Terms and definitions 1 4 Principle 2 5 Device 2 5:1 Cylindrical or flat sample holder material 2 5:2 The diameter of the cylindrical sample holder and the length of the flat sample holder 2 5:3 Low-temperature thermostat container for measuring sample resistance (R2) 2 6 Sample preparation 3 7 Data collection and analysis 3 7:1 Room temperature resistance (R1) 3 7:2 Resistance (R2 or R*2) just above the superconducting transition temperature 3 7:3 Bending strain correction of R*2 measurement value of Nb-Ti composite superconductor 5 7:4 Residual resistance ratio (RRR) 5 8 Uncertainty and stability of test methods 6 8:1 Temperature 6 8:2 Voltage 6 8:3 Current 6 8:4 Size 6 9 Test report 6 9:1 RRR value 6 9:2 Sample 6 9:3 Test conditions 7 Appendix A (informative appendix) Additional information about RRR measurement 8 Appendix B (informative appendix) Uncertainty considerations 14 Appendix C (informative appendix) Uncertainty evaluation of the test method for the RRR value of Nb-Ti and Nb3Sn composite superconductors 18 Reference 23ForewordThis standard was drafted in accordance with the rules given in GB/T 1:1-2009: This standard replaces GB/T 25897-2010 "Superconductivity: Determination of the Residual Resistance Ratio of Niobium-Titanium Composite Superconductors", and is compatible with GB/T 25897-2010 Compared with:2010, the main technical changes are as follows: ---Added the measurement method of the residual resistance ratio of niobium to tin (Nb3Sn) (see full text); ---Modified the minimum distance between the two voltage contacts during sample preparation from 25mm to 15mm (see Chapter 6,:2010 Chapter 6 of the edition); ---Modified the current density of the input current when measuring room temperature resistance, from 0:1A/mm2~1A/mm2 to 0:1A/mm2~ 2A/mm2 (see 7:1, 7:1 in:2010 edition); ---Modified the content of Appendix A (A:1 is the:2010 version of A:6; A:3 is the:2010 version of A:4, and adds b) and e) 4); A:4 is the:2010 version of A:1; the:2010 version of A:3 is deleted); ---Replaced most of the contents of Appendix B (the terms and definitions in the:2010 edition of B:2 were deleted, and B:3 and B:4 were added); ---Added Appendix C: This standard uses the translation method equivalent to IEC 61788-4:2020 "Superconductivity Part 4: Measurement of Residual Resistance Ratio Niobium-Ti (Nb-Ti) Measurement of residual resistance ratio of composite superconductor with niobium and tin (Nb3Sn)": The Chinese documents that have a consistent correspondence with the international documents cited in this standard are as follows: ---GB/T 2900:100-2017 Superconductivity in electrical engineering terms (IEC 60050-815:2015, IDT): This standard has made the following editorial changes: ---Modify the standard name to "Residual resistance ratio measurement of niobium-titanium (Nb-Ti) and niobium tin (Nb3Sn) composite superconductor residual resistance Ratio measurement: Please note that certain contents of this document may involve patents: The issuing agency of this document is not responsible for identifying these patents: This standard was proposed by the Chinese Academy of Sciences: This standard is under the jurisdiction of the National Superconducting Standardization Technical Committee (SAC/TC265): Drafting organizations of this standard: Western Superconducting Materials Technology Co:, Ltd:, Institute of Physics, Chinese Academy of Sciences, Institute of Engineering and Technology Co:, Ltd:, Huazhong University of Science and Technology, Guangdong Power Grid Co:, Ltd: Electric Power Research Institute, Institute of Plasma Physics, Chinese Academy of Sciences: The main drafters of this standard: Zhu Yanmin, Wu Bo, Feng Ran, Faye Wong, Li Jie, Zheng Minghui, Tan Yunfei, Song Meng, Liu Huajun: The previous versions of the standard replaced by this standard are as follows: ---GB/T 25897-2010:IntroductionIn niobium-titanium (Nb-Ti) and niobium tin (Nb3Sn) composite superconductors, copper (Cu), copper/copper-nickel (Cu/Cu-Ni) or aluminum (Al) are both used as The matrix material is also used as a stabilizing material: When the superconductor fails locally, it can play a role of shunting, and can The heat is transferred to the surrounding cooling medium, making it possible for the superconductor to recover its superconducting properties: Therefore, the resistance of the base material at low temperature Rate is an important characteristic index of composite superconducting materials, which is related to the stability and AC loss of superconducting materials: The residual resistance ratio is defined as The ratio of the resistance value of the composite superconductor at room temperature to the resistance value just above the superconducting transition temperature: This standard specifies the test method for the residual resistance ratio of Nb-Ti and Nb3Sn composite superconductors: The composite superconductor just exceeds the superconducting transition The resistance value at temperature is measured using the curve method: Other methods of measuring the resistance are described in A:3: Residual resistance ratio measurement niobium-titanium (Nb-Ti) And niobium tin (Nb3Sn) composite superconductor Residual resistance ratio measurement1 ScopeThis standard specifies the copper (Cu), copper-nickel (Cu-Ni), copper/copper-nickel (Cu/Cu-Ni) matrix and aluminum under the condition of no strain and no applied magnetic field: (Al) Test method for residual resistance ratio (RRR) of niobium-titanium (Nb-Ti) and niobium-three-tin (Nb3Sn) composite superconductors in the matrix: This standard applies to The residual resistance ratio is less than 350, the cross section is less than 3mm2, and the residual resistance ratio of the integrated superconductor with rectangular or circular cross section is measured: the amount: For the Nb3Sn composite superconductor, the sample undergoes reaction heat treatment:2 Normative referencesThe following documents are indispensable for the application of this document: For dated reference documents, only the dated version applies to this article Pieces: For undated references, the latest version (including all amendments) applies to this document: IEC 60050-815 International Electrotechnical Term (IEV) Part 815: Superconductivity (InternationalElectrotechnicalVo- cabulary-Part 815:Superconductivity)3 Terms and definitionsThe following terms and definitions defined by IEC 60050-815 apply to this document: ISO and IEC maintain a terminology database for standardization at the following address: ● IEC Electropedia: http://www:electropedia:org ● ISO online browsing platform: http://www:iso:org/obp 3:1 Residual resistance ratio residualresistanceratio;RRR The ratio of the resistance value at room temperature to the resistance value just above the superconducting transition temperature: Note: This standard stipulates that the resistance of Nb-Ti and Nb3Sn composite superconductors at 293K (20℃) is room temperature resistance: The residual resistance ratio of the composite superconductor is Formula (1) is calculated: rRRR = R1 R2 (1) Where: rRRR---the residual resistance ratio of the composite superconductor; R1 --- the resistance of the composite superconductor at 293K (20℃); R2 ---The resistance of the composite superconductor measured under the condition of no strain and no applied magnetic field just above the superconducting transition temperature: Figure 1 shows a schematic diagram of the measurement curve of sample resistance versus temperature at low temperature: ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 25897-2020_English be delivered?Answer: Upon your order, we will start to translate GB/T 25897-2020_English as soon as possible, and keep you informed of the progress. 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