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GB/T 39278-2020 English PDF

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US$1149.00 · In stock
Delivery: <= 8 days. True-PDF full-copy in English will be manually translated and delivered via email.
GB/T 39278-2020: Method for measuring the shielding effectiveness of shielding enclosures having all dimensions between 0.1 m and 2 m
Status: Valid

Standard ID	USD	BUY PDF	Lead-Days	Standard Title (Description)	Status
GB/T 39278-2020	1149	Add to Cart	8 days	Method for measuring the shielding effectiveness of shielding enclosures having all dimensions between 0.1 m and 2 m	Valid

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Basic data

Standard ID: GB/T 39278-2020 (GB/T39278-2020)
Description (Translated English): Method for measuring the shielding effectiveness of shielding enclosures having all dimensions between 0.1 m and 2 m
Sector / Industry: National Standard (Recommended)
Classification of Chinese Standard: L06
Classification of International Standard: 33.100.10
Word Count Estimation: 62,642
Date of Issue: 2020-11-19
Date of Implementation: 2021-06-01
Regulation (derived from): National Standard Announcement No. 26 of 2020
Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration

GB/T 39278-2020: Method for measuring the shielding effectiveness of shielding enclosures having all dimensions between 0.1 m and 2 m

---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.
(Measuring method of shielding effectiveness of 0:1m～2m shielding shell) ICS 33:100:10 L06 National Standards of People's Republic of China Measuring method of shielding effectiveness of 0:1m~2m shielding shell 2020-11-19 released 2021-06-01 implementation State Administration for Market Regulation Issued by the National Standardization Management Committee

Preface Ⅲ 1 Scope 1 2 Normative references 1 3 Terms and definitions 1 4 Preparation before measurement 2 4:1 Background 2 4:2 Test Plan 2 4:3 Equipment calibration 2 4:4 Reference level 2 4:5 Dynamic range 2 4:6 Personnel in the shielded enclosure 3 4:7 Initial test of shielding effectiveness 3 4:8 Determination of measurement results 3 5 Measurement method selection 3 6 Measurement method of shielding effectiveness of 0:75m~2m shielding shell 4 6:1 Recommended measurement frequency 4 6:2 Calculation of measurement results 4 6:3 Preparation for measurement 5 6:4 9kHz~30MHz frequency band measurement 5 6:5 Measurement in frequency band above 30MHz 9 7 Measuring method of shielding effectiveness of small physical size (< 0:75m) and electrically large shielding shell 14 7:1 Overview 14 7:2 Measuring equipment 15 7:3 Confirmation of mixing chamber 15 7:4 Measuring frequency 15 7:5 Measuring principle of frequency stirring 15 7:6 Selection criteria for frequency stirring bandwidth 15 7:7 The receiving antenna in the tested shielded shell 16 7:8 Antennas in the external mixing chamber 16 7:9 Measuring arrangement 16 7:10 Calculation of shielding effectiveness 17 7:11 Calculation of the average value 18 7:12 Calibration of coaxial cable 19 8 Measurement uncertainty 19 9 Test report 19 Appendix A (informative appendix) Initial test and improvement 21 Appendix B (informative appendix) Use the magnetic field measurement method (≤300MHz) to measure the shielding effectiveness of small and electrically small shielded enclosures Appendix C (informative appendix) Electrically small-sized shielded enclosure in mixing chamber 29 Appendix D (informative appendix) Application of absorbing materials in the measurement of shielding effectiveness of equipment shielding shells 32 Appendix E (Normative Appendix) Internal Radiation Law 36 Appendix F (informative appendix) Other relevant information 40 Appendix G (Normative Appendix) Shielding Effectiveness Calculation Formula of 0:75m~2m Shielding Shell 42 Appendix H (Informative Appendix) Shielding Effectiveness Measurement Basis of 0:75m~2m Shielding Shell 44 Appendix I (informative appendix) Working principle of monopole antenna mounted on the wall 48 Appendix J (Normative Appendix) Impedance Mismatch Correction 53 Appendix K (informative appendix) Isolated monopole antennas used in external mixing chambers 56

Foreword

This standard was drafted in accordance with the rules given in GB/T 1:1-2009: 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 and managed by the National Radio Interference Standardization Technical Committee (SAC/TC79): Drafting organizations of this standard: China Electronics Standardization Institute, Southeast University, Beijing Daze Technology Co:, Ltd:, Anfang Hi-Tech Electromagnetic Safety All Technology (Beijing) Co:, Ltd:, Beijing Institute of Radio Measurement and Testing, and Shanghai Electrical Apparatus Research Institute: The main drafters of this standard: Zhao Lei, Zhou Zhongyuan, Zhou Xiang, Sha Changtao, Li Lijia, Lu Zhiheng, Shen Tao, Ye Chang, Zhang Fengxian: Measuring method of shielding effectiveness of 0:1m~2m shielding shell

1 Scope

This standard specifies the measurement method for the shielding effectiveness of 0:1m~2m shielded enclosures: This standard is applicable to the measurement of shielding effectiveness of 0:1m~2m shielded enclosures:

2 Normative references

The 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: GB/T 4365 Electrotechnical terms electromagnetic compatibility GB 8702 Electromagnetic environment control limit GB/T 12190 Measurement method of shielding effectiveness of electromagnetic shielding room GB/T 17626:21 Electromagnetic compatibility test and measurement technology mixing chamber test method

3 Terms and definitions

The following terms and definitions defined in GB/T 4365 and GB/T 12190 apply to this document: 3:1 Electricalylarge The shielding shell supports no less than 60 modes at the frequency point of interest: 3:2 Electricalysmal The maximum side length of the shielding shell is less than one-tenth of the wavelength corresponding to the frequency point of interest: 3:3 Frequencystirring The method of changing the composition of the field mode in the cavity by changing the frequency: 3:4 Mode A solution of Maxwell's equations corresponding to a field distribution in a given space: 3:5 Mechanicalstirring The position change of the mechanical device (stirrer) made of low-loss conductive material changes the boundary conditions of the cavity, thereby changing the cavity The method of field mode composition: 3:6 Modestirring The method of changing the field mode composition in the cavity by changing the frequency, boundary conditions, or the location of the source: 3:7 Parent structure A fixing device or structure used to install the shielded shell under test: ......

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Tips & Frequently Asked Questions:

Question 1: How long will the true-PDF of GB/T 39278-2020_English be delivered?

Answer: Upon your order, we will start to translate GB/T 39278-2020_English as soon as possible, and keep you informed of the progress. The lead time is typically 5 ~ 8 working days. The lengthier the document the longer the lead time.

Question 2: Can I share the purchased PDF of GB/T 39278-2020_English with my colleagues?

Answer: Yes. The purchased PDF of GB/T 39278-2020_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.

Question 3: Does the price include tax/VAT?

Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countries

Question 4: Do you accept my currency other than USD?

Answer: Yes. If you need your currency to be printed on the invoice, please write an email to Sales@ChineseStandard.net. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.