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GB/T 16840.2-2021 English PDF (GB 16840.2-1997, GB/T 16840.2-1997)

GB/T 16840.2-2021_English: PDF (GB/T16840.2-2021)
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GB/T 16840.2-2021English119 Add to Cart 3 days [Need to translate] Technical determination methods for electrical fire evidence -- Part 2: Residual magnetism method Valid GB/T 16840.2-2021
GB 16840.2-1997English175 Add to Cart 0--9 seconds. Auto-delivery [GB/T 16840.2-1997] Technical determination method for electrical fire cause. Part 2: Recidual magnetic method Obsolete GB 16840.2-1997


BASIC DATA
Standard ID GB/T 16840.2-2021 (GB/T16840.2-2021)
Description (Translated English) Technical determination methods for electrical fire evidence -- Part 2: Residual magnetism method
Sector / Industry National Standard (Recommended)
Classification of Chinese Standard C80; C89
Classification of International Standard 13.220.20
Word Count Estimation 6,666
Date of Issue 2021-08-20
Date of Implementation 2021-08-20
Older Standard (superseded by this standard) GB/T 16840.2-1997
Drafting Organization Emergency Management Department Shenyang Fire Research Institute, Emergency Management Department Tianjin Fire Research Institute, Emergency Management Department Shanghai Fire Research Institute, Emergency Management Department Sichuan Fire Research Institute
Administrative Organization National Fire Standardization Technical Committee (SAC/TC 113)
Proposing organization Ministry of Emergency Management of the People's Republic of China
Issuing agency(ies) State Administration for Market Regulation, National Standardization Administration

BASIC DATA
Standard ID GB 16840.2-1997 (GB16840.2-1997)
Description (Translated English) [GB/T 16840.2-1997] Technical determination method for electrical fire cause. Part 2: Recidual magnetic method
Sector / Industry National Standard
Classification of Chinese Standard C82
Classification of International Standard 13.220
Word Count Estimation 7,770
Date of Issue 1997-06-03
Date of Implementation 1998-05-01
Drafting Organization Shenyang Fire Research Institute Ministry of Public Security
Administrative Organization Standardization Technical Committee of the Sixth National Fire Protection Sub-Committee
Proposing organization National Fire Standardization Technical Committee
Issuing agency(ies) State Bureau of Technical Supervision
Summary This Chinese standard specifies the definitions, principles, equipment and apparatus, method steps, judgment and inspection and identification of written procedures should be performed. This standard applies to electrical fire in the investigation of the reasons for the fire scene fire power point method to find short arcing and lightning arcing conditions, according to data decision circuit and lightning remanence generation, further analysis of the relationship with the cause of the fire.



GB/T 16840.2-2021 Technical determination methods for electrical fire evidence - Part 2.Residual magnetism method ICS 13.220.20 CCSC80/89 National Standards of People's Republic of China Replace GB/T 16840.2-1997 Technical Appraisal Method of Electrical Fire Trace Material Evidence Part 2.Remanence Detection Method Released on 2021-08-20 2021-08-20 implementation State Administration of Market Supervision and Administration Issued by the National Standardization Management Committee Table of contents Foreword Ⅰ Introduction Ⅱ 1 Scope 1 2 Normative references 1 3 Terms and definitions 1 4 Principle 1 5 Apparatus, equipment and reagents 1 5.1 Instrument 1 5.2 Equipment 2 5.3 Reagent 2 6 Inspection material 2 6.1 Types of inspection materials 2 6.2 Material selection 2 7 Method and Step 2 7.1 Preparation 2 7.2 Measurement operation 2 8 Criterion 3 8.1 Data Judgment 3 8.2 Comparison Judgment 3 8.3 Determination of magnetization law 3 Preface This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1.Structure and Drafting Rules of Standardization Documents" Drafting. This document is the second part of GB/T 16840 "Technical Appraisal Method for Electrical Fire Trace Material Evidence". GB/T 16840 has been released The following parts. ---Part 1.Macro Law; ---Part 2.Remanence detection method; ---Part 3.Auger analysis method; ---Part 4.Metallographic Analysis; ---Part 5.Identification and extraction methods of electrical fire material evidence; ---Part 6.SEM microscopic morphology analysis method; ---Part 7.EDS component analysis method; ---Part 8.Thermal analysis method. This document replaces GB/T 16840.2-1997 "Technical Appraisal Method for the Causes of Electrical Fire Part 2.Residual Magnetism Method", and is compatible with GB/T Compared with 16840.2-1997, in addition to structural adjustments and editorial changes, the main technical changes are as follows. --- Changed the scope of application (see Chapter 1, Chapter 1 of the.1997 edition); --- Added a chapter "Normative Reference Documents" (see Chapter 2); --- Deleted the terms and definitions of "residual magnetism data" and "fired wire short-circuit residual magnetism", and changed the term "lightning fuse" to "lightning strike melting" "Marks", the terms and definitions of "remanent magnetism" have been added (see Chapter 3, Chapter 2 of the.1997 edition); ---Relevant content of the principle of remanence detection method has been modified and improved (see Chapter 4, Chapter 3 of the.1997 edition); ---Added the instruments and reagents needed in the analysis process, as well as their parameters (see Chapter 5, Chapter 4 of the.1997 edition); --- Deleted "lightning residual magnetism" and "fire wire short-circuit residual magnetism judgment" (see Chapter 8,.1997 edition of 6.1.4, 6.4); --- Deleted the written procedures that should be performed when submitting for inspection and appraisal (see Chapter 7 of the.1997 edition). Please note that some of the contents of this document may involve patents. The issuing agency of this document is not responsible for identifying patents. This document was proposed by the Ministry of Emergency Management of the People's Republic of China. This document is under the jurisdiction of the National Fire Standardization Technical Committee (SAC/TC113). This document was drafted by. Shenyang Fire Research Institute of the Ministry of Emergency Management, Tianjin Fire Research Institute of the Ministry of Emergency Management, and Shanghai Fire Protection of the Ministry of Emergency Management Research Institute, Sichuan Fire Research Institute of Emergency Management Department. The main drafters of this document. Di Man, Zhao Changzheng, Gao Wei, Qi Zibo, E Dazhi, Zhang Ming, Xia Dawei, Zhang Liang, Zhang Lei, Peng Bo. The previous versions of this document and the documents replaced are as follows. ---GB/T 16840.2-1997; ---This is the first revision. introduction The identification of electrical fire evidence is an important part of the investigation of the cause of fire by emergency rescue and firefighting agencies, especially when it is accompanied by national The improvement of the legal system of the family, the enhancement of citizens’ awareness of the legal system, the identification of physical evidence has been used as strong evidence for the identification of the cause of the fire, and it is a fire rescue agency. The determination of the cause of the fire provides scientific, fast and accurate technical support. In this regard, my country has established a technology for evidence of electrical fire traces. National standard system for identification methods. In this standard system, GB/T 16840 "Technical Appraisal Method for Electrical Fire Trace Material Evidence" is a guide for me The method and basis for the relevant agencies of the country to engage in the identification of electrical fire evidence is planned to consist of eight parts, and the purpose is to establish Trace physical evidence for macro analysis, remanence analysis, Auger analysis, metallographic analysis, physical evidence identification and extraction, SEM microscopic morphology analysis, and component analysis And the method and basis for thermal analysis. ---Part 1.Macro Law; ---Part 2.Remanence detection method; ---Part 3.Auger analysis method; ---Part 4.Metallographic Analysis; ---Part 5.Identification and extraction methods of electrical fire material evidence; ---Part 6.SEM microscopic morphology analysis method; ---Part 7.EDS component analysis method; ---Part 8.Thermal analysis method. Remanence detection is an analytical method used in the identification of electrical fire traces in my country. This document is in the scientific research project "Application Research on identification of wire short circuit and lightning fire caused by remanence method" basic test data and years of actual fire evidence Proposed on the basis of. This revision of GB/T 16840.2 focused on the rigor and standardization of document writing and presentation, and improved Part of the content enables fire investigators to have evidence to rely on when adopting the residual magnetism detection method and improve work efficiency. Technical Appraisal Method of Electrical Fire Trace Material Evidence Part 2.Remanence Detection Method 1 Scope This document specifies the principles, instruments, equipment and materials, inspection materials and methods of the residual magnetism detection method in the technical identification method of electrical fire traces. And steps, criteria. This document is applicable to the investigation of fire accidents, in the case that no short-circuit melting marks or lightning strike melting marks are found at the construction fire site, according to the ferromagnetic The residual magnetism data obtained from the detection of the sexual metal conductor determines whether an excessive current short circuit or lightning strike occurs. 2 Normative references The contents of the following documents constitute the indispensable clauses of this document through normative references in the text. Among them, dated quotations Only the version corresponding to that date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to This document. GB/T 16840.1 Technical Appraisal Method of Electrical Fire Trace Material Evidence Part 1.Macro Method 3 Terms and definitions The following terms and definitions defined in GB/T 16840.1 apply to this document. 3.1 Residualmagnetism The magnetism retained by the ferromagnetic body after it is magnetized by the magnetic field formed by the short-circuit current of the wire or the lightning current. 3.2 Lightning melt mark meltedmark induced by lightning Metal melting traces formed by high temperature action of lightning current. 4 Principle Due to the magnetic effect of the current, a magnetic field is generated in the space around the wire or metal conductor through which the current flows. When the magnetic field escapes, the ferromagnet still maintains a certain degree of magnetism. After the ferromagnet in the magnetic field is magnetized, the residual magnetic induction intensity and the current and distance Away from related. Usually, the current in the wire under normal conditions, although it will also generate a magnetic field, but its strength is small, and the remanence left on the ferromagnetic body also has limit. When a short circuit, a lightning strike, or a building is struck by lightning, an abnormally large current will be generated, resulting in a magnetic field with considerable strength. The ferromagnet in the magnetic field is also subject to strong magnetization and maintains greater magnetism. 5 Apparatus, equipment and reagents 5.1 Apparatus Magnetic field detection equipment. the range is 0mT~100mT, the resolution is not less than 0.01mT, and the operating temperature is -20℃~40℃. ......


GB/T 16840.2-1997 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 130.220 C 82 GB 16840.2-1997 Technical Determination Methods for Electrical Fire Cause - Part 2: Residual Magnetic Method ISSUED ON: JUNE 03, 1997 IMPLEMENTED ON: MAY 01, 1998 Issued by: State Bureau of Technical Supervision According to the Standardization Administration of China Announcement No.7 of 2017, it is converted into recommended standard Table of Contents Foreword ... 3 1 Scope ... 4 2 Definitions ... 4 3 Principle ... 4 4 Apparatus ... 5 5 Method Procedures... 5 6 Judgment ... 7 7 Written Procedures to be Followed during Inspection and Appraisal ... 8 Technical Determination Methods for Electrical Fire Cause – Part 2: Residual Magnetic Method 1 Scope This Standard specifies definitions, principles, apparatus, method procedures, judgments, and written procedures to be performed during inspection and appraisal. This Standard is applicable to determine the occurrence of short-circuit and lightning based on data of residual magnetism under the condition that melted mark induced by short-circuit and lightning cannot be found at the fire site of the fire point when investigating the cause of electrical fires; and further analyze relationship with the cause of the fire. 2 Definitions For the purpose of this Standard, the following definitions apply. 2.1 Data of residual magnetism The magnetic value that the ferromagnetic body retains after being magnetized by the magnetic field formed by the short-circuit current of the wire and the lightning current. The unit is millitesla (mT). 2.2 Melted mark induced by lightning The melted marks that are formed on the surface of metal by the high temperature of lightning. 2.3 Residual magnetism in conducting wire short circuit caused by fire burning The magnetism of the ferromagnetic body that is maintained after being magnetized by the magnetic field that is formed by the short-circuit of copper-aluminum wire that is charged under high-temperature of fire. 3 Principle Due to the magnetic effect of the current, a magnetic field is generated in the space around the current; and the ferromagnetic body in the magnetic field is magnetized. When the magnetic field escapes, the ferromagnetic body still maintains a certain degree of magnetism. 5.2.1 Location As the test specimen, it shall be taken from the fire point or around the wire of the fire part that has been confirmed on the site. The distance between the specimen and the wire should not exceed 20mm; but for the site with the possibility of thunder and lightning, it may be extracted according to the actual situation; and it is not restricted by the location. 5.2.2 Taking photos Before extracting the samples, take photos on the site. The method of taking photos may be divided into two items, namely, the orientation of the specimen and the close- up of the specimen. 5.2.3 Extraction --- Specimens that are fixed on walls or other objects shall not be bent, beaten, or dropped during extraction; --- Specimens with lower fire temperature should be extracted; --- Specimens that are located near the magnetic material shall not be extracted; --- When it is confirmed that the line has been short-circuited in the past, it shall not be extracted; --- If it is inconvenient to extract, it may be tested at the original location of the specimen. 5.3 Storage The extracted specimens should be put in a sampling bag for safekeeping; and the specimen name and extraction location shall be indicated; and shall not be mixed with magnetic materials or other objects. 5.4 Measurement 5.4.1 Dirt removal Use water and solvent to remove carbon dust and dirt on the specimen surface before measurement. 5.4.2 Preparation for measurement According to the instructions of the instrument, turn on the power of the instrument, and get ready after calibration and preheating. 5.4.3 Operation The residual magnetism at the tip of the lightning rod is not large, namely, 0.6~1.0mT. The data of residual magnetism for stray iron parts, nails, rebars, and metal pipes in the lightning channel are all between 1.5 and 10mT. The above-mentioned data are obtained from experiments and on-site lightning detection, and may be used as a reference for judgment. 6.2 Comparison judgment It is judged by comparison on the site that if there are lines passing through the same two facilities, but one has residual magnetism and the other has not, it proves that the wire with the residual magnetism has been short-circuited. 6.3 Judgment of magnetization law The strength of ferromagnetic body magnetism is related to the distance from the wire (short circuit). The closer to the wire, the stronger the magnetism. If the law from strong to weak can be found during measurement, and then combined with the measured data, it may be further determined whether the wire has been short-circuited. 6.4 Judgment of the residual magnetism in conducting wire short circuit caused by fire burning If conducting wire short-circuit caused by fire burning, it shall also generate a magnetic file and keep the ferromagnetic body magnetic. To determine whether the short-circuit is formed before the fire or the short-circuit is formed by fire burning, the fire source shall be checked, and the judgment shall be made according to the actual situation of the site. 7 Written Procedures to be Followed during Inspection and Appraisal 7.1 When submitting the inspection, the inspection organism shall first fill in the application form for the technical appraisal of the cause of electrical fire, which includes the name, address, contact person of the organism applying for appraisal; name of the unit that catches fire, sample name, quantity, sampling location, sampler, and purpose of appraisal. 7.2 The appraisal unit shall fill in the sample receipt, task list, reception record and original record after accepting the appraisal task. 7.3 After the completion of the appraisal, fill in the appraisal conclusion in the appraisal report approval form, signed by the person in charge of the laboratory, and report to the leader for approval after the quality review is correct. ......


GB/T 16840.2-1997 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 130.220 C 82 GB 16840.2-1997 Technical Determination Methods for Electrical Fire Cause - Part 2: Residual Magnetic Method ISSUED ON: JUNE 03, 1997 IMPLEMENTED ON: MAY 01, 1998 Issued by: State Bureau of Technical Supervision According to the Standardization Administration of China Announcement No.7 of 2017, it is converted into recommended standard Table of Contents Foreword ... 3 1 Scope ... 4 2 Definitions ... 4 3 Principle ... 4 4 Apparatus ... 5 5 Method Procedures... 5 6 Judgment ... 7 7 Written Procedures to be Followed during Inspection and Appraisal ... 8 Technical Determination Methods for Electrical Fire Cause – Part 2: Residual Magnetic Method 1 Scope This Standard specifies definitions, principles, apparatus, method procedures, judgments, and written procedures to be performed during inspection and appraisal. This Standard is applicable to determine the occurrence of short-circuit and lightning based on data of residual magnetism under the condition that melted mark induced by short-circuit and lightning cannot be found at the fire site of the fire point when investigating the cause of electrical fires; and further analyze relationship with the cause of the fire. 2 Definitions For the purpose of this Standard, the following definitions apply. 2.1 Data of residual magnetism The magnetic value that the ferromagnetic body retains after being magnetized by the magnetic field formed by the short-circuit current of the wire and the lightning current. The unit is millitesla (mT). 2.2 Melted mark induced by lightning The melted marks that are formed on the surface of metal by the high temperature of lightning. 2.3 Residual magnetism in conducting wire short circuit caused by fire burning The magnetism of the ferromagnetic body that is maintained after being magnetized by the magnetic field that is formed by the short-circuit of copper-aluminum wire that is charged under high-temperature of fire. 3 Principle Due to the magnetic effect of the current, a magnetic field is generated in the space around the current; and the ferromagnetic body in the magnetic field is magnetized. When the magnetic field escapes, the ferromagnetic body still maintains a certain degree of magnetism. 5.2.1 Location As the test specimen, it shall be taken from the fire point or around the wire of the fire part that has been confirmed on the site. The distance between the specimen and the wire should not exceed 20mm; but for the site with the possibility of thunder and lightning, it may be extracted according to the actual situation; and it is not restricted by the location. 5.2.2 Taking photos Before extracting the samples, take photos on the site. The method of taking photos may be divided into two items, namely, the orientation of the specimen and the close- up of the specimen. 5.2.3 Extraction --- Specimens that are fixed on walls or other objects shall not be bent, beaten, or dropped during extraction; --- Specimens with lower fire temperature should be extracted; --- Specimens that are located near the magnetic material shall not be extracted; --- When it is confirmed that the line has been short-circuited in the past, it shall not be extracted; --- If it is inconvenient to extract, it may be tested at the original location of the specimen. 5.3 Storage The extracted specimens should be put in a sampling bag for safekeeping; and the specimen name and extraction location shall be indicated; and shall not be mixed with magnetic materials or other objects. 5.4 Measurement 5.4.1 Dirt removal Use water and solvent to remove carbon dust and dirt on the specimen surface before measurement. 5.4.2 Preparation for measurement According to the instructions of the instrument, turn on the power of the instrument, and get ready after calibration and preheating. 5.4.3 Operation The residual magnetism at the tip of the lightning rod is not large, namely, 0.6~1.0mT. The data of residual magnetism for stray iron parts, nails, rebars, and metal pipes in the lightning channel are all between 1.5 and 10mT. The above-mentioned data are obtained from experiments and on-site lightning detection, and may be used as a reference for judgment. 6.2 Comparison judgment It is judged by comparison on the site that if there are lines passing through the same two facilities, but one has residual magnetism and the other has not, it proves that the wire with the residual magnetism has been short-circuited. 6.3 Judgment of magnetization law The strength of ferromagnetic body magnetism is related to the distance from the wire (short circuit). The closer to the wire, the stronger the magnetism. If the law from strong to weak can be found during measurement, and then combined with the measured data, it may be further determined whether the wire has been short-circuited. 6.4 Judgment of the residual magnetism in conducting wire short circuit caused by fire burning If conducting wire short-circuit caused by fire burning, it shall also generate a magnetic file and keep the ferromagnetic body magnetic. To determine whether the short-circuit is formed before the fire or the short-circuit is formed by fire burning, the fire source shall be checked, and the judgment shall be made according to the actual situation of the site. 7 Written Procedures to be Followed during Inspection and Appraisal 7.1 When submitting the inspection, the inspection organism shall first fill in the application form for the technical appraisal of the cause of electrical fire, which includes the name, address, contact person of the organism applying for appraisal; name of the unit that catches fire, sample name, quantity, sampling location, sampler, and purpose of appraisal. 7.2 The appraisal unit shall fill in the sample receipt, task list, reception record and original record after accepting the appraisal task. 7.3 After the completion of the appraisal, fill in the appraisal conclusion in the appraisal report approval form, signed by the person in charge of the laboratory, and report to the leader for approval after the quality review is correct. ......

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