GB/T 19531.2-2026 Technical requirements for the observation environment of seismic stations—Part 2:Electromagnetic observation English, Anglais, Englisch, Inglés, えいご
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ICS 13.220.10
CCS H 57
National Standard of the People's Republic of China
GB/T 19531.2-2026
Replaces GB/T 19531.2-2004
Technical requirements for the observation environment of seismic stations - Part 2: Electromagnetic observation
地震台站观测环境技术要求 第2部分：电磁观测
Issue date: 2026-01-28 Implementation date: 2027-02-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
Introduction
1 Scope
2 Normative References
3 Terms and Definitions
4 Technical Requirements and Test Methods for the Electromagnetic Observational Environment of Seismic Stations
5 Minimum Distance Between Electromagnetic Disturbance Sources and Electromagnetic Observation Facilities of Seismic Stations
Annex A (Normative) Test Method for the Impact of Electromagnetic Disturbance Sources on the Geoelectric Field Observational Environment
Annex B (Normative) Test Method for the Impact of Event-Type Magnetic Disturbance Sources on the Geomagnetic Field Observational Environment
Annex C (Normative) Test Method for the Impact of Short-Period Magnetic Disturbance Sources on the Geomagnetic Field Observational Environment
Annex D (Normative) Test Method for the Impact of Electromagnetic Disturbance Sources on the Geoelectrical Resistivity Observational Environment
Annex E (Normative) Calculation Method for the Minimum Distance Between Buildings or Structures Containing Ferromagnetic Materials and Geomagnetic Observation Points
Bibliography
Technical Requirements for the Observational Environment of Seismic Stations — Part 2: Electromagnetic Observation
1 Scope
This document specifies the technical specifications for the electromagnetic observational environment of seismic stations, and the minimum distance between electromagnetic disturbance sources and electromagnetic observation facilities of seismic stations. It also describes the corresponding test and calculation methods.
This document applies to the site selection and environmental protection for geoelectric field observation, geomagnetic field observation, and geoelectrical resistivity observation facilities of seismic stations.
2 Normative References
The following documents contain provisions which, through normative reference in this text, constitute essential provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 917 Marking Rules for Highway Route and Numbering of National Trunk Highways
GB/T 18207 (all parts) Terms Relating to Protecting Against and Mitigating Earthquake Disasters
GB/T 28026.2 Railway Applications — Fixed Installations — Electrical Safety, Earthing and Return Circuit — Part 2: Provisions Against the Effects of Stray Currents Caused by DC Traction Power Supply Systems
DB/T 18.1 Specification for the Construction of Seismic Station — Geoelectrical Station — Part 1: Geoelectrical Resistivity Station
DB/T 18.2 Specification for the Construction of Seismic Station — Geoelectrical Station — Part 2: Geoelectric Field Station
DB/T 33.1 Geoelectrical Observation Method for Earthquake — Geoelectrical Resistivity Observation — Part 1: Single Separation Configuration Observation
DB/T 34 Geoelectrical Observation Method for Earthquake — Geoelectric Field Observation
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in GB/T 18207 (all parts) and the following apply.
3.1
electromagnetic disturbance
A non-natural electromagnetic phenomenon that may cause degradation in the performance of a device, equipment, or system, or cause adverse effects on living or non-living matter.
NOTE: Electromagnetic disturbance may be electromagnetic noise, an unwanted signal, or a change in the propagation medium itself.
[SOURCE: GB/T 4365-2024, 3.1.5, modified]
3.2
static magnetic disturbance
A relatively stable magnetic field variation phenomenon, superimposed on the natural geomagnetic field, caused by various objects containing ferromagnetic materials or stable direct currents.
3.3
event-type magnetic disturbance
A sudden magnetic field variation phenomenon caused by non-natural electromagnetic sources.
3.4
short period magnetic disturbance
A magnetic field variation phenomenon, with an apparent period of 0.1 s to 600 s, caused by non-natural electromagnetic sources.
3.5
commercial electromagnetic disturbance
Electromagnetic disturbance (3.1) generating an electromagnetic field at 50 Hz and its harmonic frequencies.
NOTE: Examples include magnetic field variations produced by facilities and objects such as high-voltage AC transmission lines, transformers, electrical appliances (including running electric trains), etc.
4 Technical Requirements and Test Methods for the Electromagnetic Observational Environment of Seismic Stations
4.1 Technical Requirements for the Geoelectric Field Observational Environment
4.1.1 The additional electric field intensity generated by non-commercial electromagnetic disturbance sources between the measuring electrodes in a geoelectric field observation site shall not exceed 0.5 mV/km.
4.1.2 The power frequency electric field intensity generated by commercial electromagnetic disturbance sources between the measuring electrodes in a geoelectric field observation site shall not exceed 1250 mV/km (peak value).
4.2 Technical Requirements for the Geomagnetic Field Observational Environment
4.2.1 The intensity of static magnetic disturbance shall not exceed 0.5 nT.
4.2.2 The intensity of event-type magnetic disturbance shall not exceed 0.1 nT.
4.2.3 The intensity of short period magnetic disturbance shall not exceed 0.1 nT.
4.3 Technical Requirements for the Geoelectrical Resistivity Observational Environment
4.3.1 The impact of non-commercial electromagnetic disturbance sources on geoelectrical resistivity observation shall not exceed 0.3%.
4.3.2 The peak value of power frequency disturbance voltage generated by commercial electromagnetic disturbance sources between the measuring electrodes in a geoelectrical resistivity observation site shall not exceed 500 mV.
4.3.3 The change in observed geoelectrical resistivity values caused by disturbance sources like metal pipeline (wire) facilities shall not exceed 0.3%.
4.4 Test Methods for the Electromagnetic Observational Environment
4.4.1 The additional electric field intensity generated by non-commercial electromagnetic disturbance sources between the measuring electrodes in a geoelectric field observation site shall be tested according to the provisions of Annex A.
4.4.2 The power frequency electric field intensity generated by commercial electromagnetic disturbance sources between the measuring electrodes in a geoelectric field observation site shall be tested according to the provisions of Annex A.
4.4.3 The intensity of event-type magnetic disturbance shall be tested according to the provisions of Annex B.
4.4.4 The intensity of short period magnetic disturbance shall be tested according to the provisions of Annex C.
4.4.5 The impact of non-commercial electromagnetic disturbance sources on geoelectrical resistivity observation shall be tested according to the provisions of Annex D.
4.4.6 The peak value of power frequency disturbance voltage generated by commercial electromagnetic disturbance sources between the measuring electrodes in a geoelectrical resistivity observation site shall be tested according to the provisions of Annex D.
5 Minimum Distance Between Electromagnetic Disturbance Sources and Electromagnetic Observation Facilities of Seismic Stations
5.1 Minimum Distance Between Buildings or Structures Containing Ferromagnetic Materials and Geomagnetic Observation Points
The minimum distance between the geometric center of a building or structure containing ferromagnetic materials and a geomagnetic observation point shall be calculated according to the provisions of Annex E.
5.2 Minimum Distance Between DC-Powered Rail Transit Systems and Electromagnetic Observation Facilities of Seismic Stations
Under the condition that the transition resistance of the DC-powered rail transit system to ground complies with GB/T 28026.2, the minimum distance between the DC-powered rail transit system and the electromagnetic observation facilities of a seismic station shall comply with the following provisions:
a) The distance from the track to the center of the geoelectric field observation site shall not be less than 80 km;
b) The distance from the track to the geomagnetic observation point shall not be less than 50 km;
c) The distance from the track to the center point of any measuring direction in the geoelectrical resistivity observation site shall not be less than 60 km.
5.3 Minimum Distance Between Railway Transport Systems and Electromagnetic Observation Facilities of Seismic Stations
5.3.1 The minimum distance between an electrified railway transport system and the electromagnetic observation facilities of a seismic station shall comply with the following provisions:
a) The distance from the track to the center of the geoelectric field observation site shall not be less than 10 km;
b) The distance from the track to the geomagnetic observation point shall not be less than 9 km;
c) The distance from the track to the center point of any measuring direction in the geoelectrical resistivity observation site shall not be less than 5 km.
5.3.2 The minimum distance between a conventional railway transport system and the electromagnetic observation facilities of a seismic station shall comply with the following provisions:
