GB/T 11684-2003 Electromagnetic environmental conditions and test methods for nuclear instruments

This standard specifies the classification, requirements and test methods of electromagnetic environment conditions for nuclear instruments to resist electromagnetic interference. This standard applies to general laboratory nuclear instruments, isotope and radiation application nuclear instruments, radioactive prospecting and mineral processing nuclear instruments, medical nuclear instruments, nuclear reactor instruments and radiation protection instruments. GB/T 11684-2003 Electromagnetic environment conditions and test methods for nuclear instruments GB/T11684-2003 standard download decompression password: www.bzxz.net

GB/T 11684—2003
This standard is a revision of GB/T11684---1989 "Electromagnetic Interference Characteristics and Test Methods for Nuclear Instruments for Reactors" (hereinafter referred to as the original standard) to apply to all nuclear instruments. According to the electromagnetic environment and electromagnetic compatibility of nuclear instruments, only the characteristics of immunity and other characteristics can be considered. According to the electromagnetic compatibility series standards such as GB/T17624, GB/T18039 and GB/T17626 (equivalent to the IEC61000 series standards), relevant contents are selected to compile this standard.
Compared with the original standard, in order to fully and completely adapt to the anti-electromagnetic interference characteristics and test methods of nuclear instruments, the electromagnetic environment classification of nuclear instruments was first added according to GB/Z18039.1-2000 "Classification of Electromagnetic Environment for Electromagnetic Compatibility Environment" (idtIEC61000-2-5). From the three basic categories of electromagnetic phenomena, namely low-frequency phenomena, high-frequency phenomena and electrostatic discharge, the important electromagnetic interference sources that can cause electromagnetic interference to nuclear instruments are selected: radiated high (radio) frequency electric field, radiated low-frequency magnetic field, electrostatic discharge, conducted low-frequency power supply voltage and frequency fluctuations and power supply voltage sag and short-term interruption, conducted high-frequency unidirectional and oscillating transients, and induced continuous wave voltage and current. The value of the electromagnetic interference level (disturbance degree) representing each disturbance source is proposed. The characteristics of the electromagnetic environment category of nuclear instruments and the disturbance degree (level) of each category of the above-mentioned disturbance sources are recommended. Finally, according to the series of standards of GB/T17626 "Electromagnetic Compatibility Test and Measurement Technology" (idtIEC61000-4), specific test methods for the above-mentioned disturbance sources are proposed. Standard operating procedures are provided for determining the electromagnetic environment and anti-electromagnetic interference items and specific test methods for various types of nuclear instruments. Regarding the requirements and test methods for the anti-electromagnetic interference of nuclear reactor instruments, the requirements and test methods for the RF injection (including light transmission impedance) test, magnetic field radiation sensitivity test, electrostatic discharge sensitivity test, and power coupling interference test of a single instrument in the original standard are replaced by Tables 1 and 2 and 5.2.1 and 5.2.2, Table 3 and 5.2.3, Table 4 and 5.2.4, Table 6 and Table 7 and 5.2.6, 5.2.7 and 5.2.8 of this standard respectively. The requirements and test methods for the ground coupling interference and DC ground injection and power coupling of the entire instrument system after installation are replaced by Tables 1 and 2 and 5.2.1 and 5.2.2, Table 6 and 5.2.6 and 5.2.7 of this standard respectively. In addition, requirements and test methods for cable charging pulse inspection (see Table C.1 and C.1 in Appendix C) and requirements and test methods for conducted interference inspection (see Table C.1 and C.2, C.3, C.4 and C.5 in Appendix C) are added for single instruments and the entire instrument system after installation. This standard also lists the immunity test levels and test methods of the IEC standards for radiation protection instruments in recent years (see Table D.1 in Appendix D). "Nuclear instrument electromagnetic environment conditions" refers to the extreme conditions of various electromagnetic phenomena characterized by interference that nuclear instruments may encounter during use. "Nuclear instrument electromagnetic environment test" is to place nuclear instruments in an artificial simulated electromagnetic environment and evaluate their performance under the corresponding electromagnetic environment conditions that they may encounter in actual use. The performance requirements of nuclear instrument products under the specified nuclear instrument electromagnetic environment conditions are given by relevant product standards. Equipment that cannot be tested as a whole can be tested separately. This standard will be combined with GB/T8993-1998 "Nuclear Instrument Environmental Conditions and Test Methods" (climate and mechanical environment) to form a series of basic standards for nuclear instruments.
Appendix A and Appendix B of this standard are informative appendices, while Appendix C and Appendix D are normative appendices. This standard was proposed by the National Technical Committee for Standardization of Nuclear Instruments. This standard is under the jurisdiction of the Nuclear Industry Standardization Institute. The unit that initiated this standard: The Second Institute of the Chinese People's Liberation Army Chemical Defense Research Institute. The main drafters of this standard: Mao Yongze, Lu Jiandong, Zou Shiya, Zhang Songshou, Luo Pingan 1 Scope
Electromagnetic environmental conditions and test methods for nuclear instruments This standard specifies the classification, requirements and test methods of electromagnetic environmental conditions for nuclear instruments to resist electromagnetic interference. GB/T 11684-2003
This standard applies to general laboratory nuclear instruments, isotope and radiation application nuclear instruments, radioactive prospecting and mineral processing nuclear instruments, medical nuclear instruments, nuclear reactor instruments and radiation protection instruments. 2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties that reach an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any undated referenced document, the latest version is applicable to this standard. GB/T4365 Electromagnetic compatibility terminology (GB/T4365—1995, idtIEC60050-161:1990) GB/T17626.2 Electromagnetic compatibility test and measurement technology Electrostatic discharge immunity test (GB/T17626.2-1998, idt IEC 61000-4-2:1995)
GB/T17626.3 Electromagnetic compatibility
1998idtIEC61000-4-3:1995)
Test and measurement technology Radio frequency electromagnetic field radiation immunity test (GB/T17626.3—GB/T17626.4 Electromagnetic compatibility
Test and measurement technology Electrical fast transient pulse group immunity test (GB/T17626.4-1998, idt IEC 61000-4-4:1995)GB/T17626.5 Electromagnetic compatibility
idt IEC 61000-4-5:1995)
GB/T17626.6 Electromagnetic compatibility
1998,idt IEC 61000-4-6:1996) Surge (impact) immunity test (GB/T17626.5-1999, test and measurement technology
test and measurement technology radio frequency field induced conducted disturbance immunity (GB/T17626.6-GB/T17626.8 Electromagnetic compatibility
test and measurement technology
idt IEC 61000-4-8:1993)
GB/T17626.11 Electromagnetic compatibility test and measurement technology (GB/T 17626.11—1999, idt IEC 61000-4-11:1994) Power frequency magnetic field immunity test (GB/T17626.8—1998, Voltage dips, short interruptions and voltage variations immunity test GB/T 17626.12
Oscillating wave immunity test (GB/T17626.12—1998, 2 Electromagnetic compatibility test and measurement technology
idt IEC 61000-4-12:1995)
3 Terms and definitions
The terms and definitions established in GB/T4365 and the following terms and definitions apply to this standard. 3.1
Electromagnetic environment environment The sum of all electromagnetic phenomena present in a given place. Note: In general, the electromagnetic environment is time-dependent and may be described using statistical methods. 3.2
Electromagnetic disturbance Any electromagnetic phenomenon that may cause a degradation in the performance of a device, equipment or system or cause damage to living or inanimate matter. Note: Electromagnetic disturbance may be electromagnetic noise, unwanted signals or changes in the propagation medium itself. 1
GB/T 11684--2003
Electromagnetic interference Electromagnetic interference caused by electromagnetic interference to reduce the performance of a device, equipment or system. Note: Disturbance and interference are cause and effect, respectively. 3.4
Electromagnetic compatibility (EMC) The ability of a device or system to operate normally in its electromagnetic environment and not cause unacceptable electromagnetic interference to anything in the environment.
Degradation (of performance) Unexpected deviation of the working performance of a device, equipment or system from normal performance. Note: "Degradation of performance" can be used for short-term or permanent failures. 3.6
Immunity (to adisturbance) The ability of a device, equipment or system to not degrade its operating performance in the presence of electromagnetic disturbance. 3.7
(Electromagnetic) Susceptibility Electromagnetic Susceptibility The inability of a device, equipment or system to operate without degradation in the presence of electromagnetic disturbance. Note: Susceptibility is the lack of immunity.
Disturbance level
The level of a given electromagnetic disturbance measured by a specified method. 3.9
Disturbance degree
The quantitative intensity specified within the range of disturbance levels corresponding to a specific electromagnetic phenomenon in the environment of concern. 4 Classification of electromagnetic environmental conditions and disturbance levels of nuclear instruments 4.1 Anti-electromagnetic disturbance measures should be taken in the design of nuclear instruments to prevent them from not working properly or causing unacceptable performance degradation in certain electromagnetic environments, especially radio frequency fields.
4.2 The purpose of the electromagnetic environment classification of nuclear instruments is to formulate specifications for the anti-electromagnetic disturbance requirements of nuclear instruments so as to obtain satisfactory electromagnetic compatibility under such disturbance sources and disturbance levels. The classification of electromagnetic environments should be based on the classification of electromagnetic phenomena that often occur in typical working places of nuclear instruments, and the test specifications of products should correspond to them. 4.3 The three basic categories of electromagnetic phenomena should be low-frequency phenomena, high-frequency phenomena and electrostatic discharge. The disturbance degree should be used as a quantitative description of electromagnetic phenomena, and the disturbance degree should be characterized by the magnitude of the different attributes of electromagnetic phenomena (such as amplitude, waveform, frequency, etc.). 4.4 According to the composition and working characteristics of nuclear instruments, the important electromagnetic phenomena (sources) that can generate electromagnetic interference include: radiated high (radio) frequency electric field, radiated low-frequency magnetic field, electrostatic discharge, conductive low-frequency power supply voltage and frequency fluctuations and power supply voltage sags and short-term interruptions, conductive high-frequency unidirectional and oscillating transients, and induced continuous wave voltage and current. Their specific source terms and disturbance degree classifications are shown in Tables 1 to 7. The test methods for Tables 1 to 5 are shown in 5.2.1 to 5.2.5, the test methods for Table 6 are shown in 5.2.6 and 5.2.7, and the test methods for Table 7 are shown in 5.2.8.
The disturbance level A in the table indicates that the electromagnetic environment is controlled to a certain extent, such as caused by the installation of buildings and equipment, or achieved by taking certain mitigation and control measures to meet special requirements. The disturbance level X refers to a more severe disturbance level than the common ones. 4.5 Table 8 lists 8 types of electromagnetic environment places, including rural residential areas, urban residential areas, commercial areas, light industrial areas, heavy industrial areas (including power plants or switch stations), transportation areas, communication centers and hospitals, which can be used for nuclear instrument work, and the corresponding electromagnetic interference source characteristics of each population of nuclear instruments. 2
Table 9 gives the interference sources of 8 types of electromagnetic environment places and the interference levels of each population of nuclear instruments. GB/T 11684—2003
4.6 The order of determining the electromagnetic interference resistance requirements of nuclear instruments should be: first refer to Table 8 to select the electromagnetic environment place category when the nuclear instrument is actually working, then select and determine the corresponding interference entry, interference source and interference level from Table 9 (the category and number of interference sources can also be determined by negotiation between the user and the manufacturer), and finally refer to Table 1? The specific disturbance level and electromagnetic phenomenon properties of each disturbance source category are determined. For examples, see B.1 in Appendix B.
5 Electromagnetic environment test methods for nuclear instruments
5.1 Reference conditions and standard test conditions
When nuclear instruments are tested under electromagnetic environment influence conditions, the reference conditions and standard test conditions are shown in Table 10. When there is no objection to the electromagnetic environment test, the test can be carried out under normal atmospheric conditions. Normal atmospheric conditions are as follows: ambient temperature: (15~35)℃;
Relative humidity: 45%~～75%;
Atmospheric pressure: (86~106)kPa.
5.2 Electromagnetic environment test methods
After determining the typical electromagnetic environment site categories that nuclear instruments may encounter during use and the disturbance levels and corresponding properties of different electromagnetic disturbance sources of each population of nuclear instruments according to 4.6, the corresponding or close test methods in 5.2.1~5.2.8 should be selected, and the test level should be adapted to the disturbance level.
For an example of the test method for determining electromagnetic disturbances of nuclear instruments, see B.2 in Appendix B.5.2.1For the test of immunity to radiated radio frequency electromagnetic fields, see GB/T 17626.3.
5.2.2For the test of immunity to conducted disturbances induced by radio frequency fields, see GB/T 17626.6.
5.2.3For the test of immunity to power frequency magnetic fields, see GB/T 17626.8.
5.2.4For the test of immunity to electrostatic discharge, see GB/T 17626.2.
5.2.5For the test of immunity to voltage dips, short interruptions and voltage variations, see GB/T 17626.11.
5.2.6For the test of immunity to electrical fast transient pulse groups, see GB/T 17626.4.
5.2.7 Surge (impact) immunity test
See GB/T17626.5.
5.2.8 Oscillating wave immunity test
See GB/T17626.12.
5.2.9 Nuclear reactor instruments have significant electromagnetic sensitivity, with long cables, low signal levels and wide bandwidth. It is necessary to combine the strict requirements of safety and reliability and treat the electromagnetic disturbance effects with caution. According to the IEC analysis of the electromagnetic environment conditions of nuclear reactor instruments, Appendix C gives the immunity requirements and test methods for nuclear reactor instruments. With the consensus of the user and the manufacturer, the immunity test items and their requirements and methods in Appendix C can also be directly selected for nuclear reactor instruments. 5.2.10 An important content of the IEC revision of the radiation protection instrument standards in recent years is the addition of the electromagnetic compatibility immunity requirements and corresponding test methods listed in Appendix D. After the user and the manufacturer reach an agreement, the immunity requirements and test methods of the corresponding radiation protection instrument can also be directly selected
5.3 Electromagnetic environment immunity test results and reports The results of various immunity tests of nuclear instruments on the electromagnetic environment can generally be divided into three categories: A, B and C. The requirements are as follows:3
GB/T 11684—2003
Class A: Nuclear instruments should continue to work normally according to performance requirements during and after the immunity test. -Class B: Nuclear instruments should continue to work normally according to performance requirements after the immunity test. Performance degradation determined and explained by the manufacturer is allowed during the immunity test.
Class C: Nuclear instruments are allowed to have temporary loss of function during and after the immunity test, but should be able to restore function automatically or by adjusting the control parts.
The nuclear instrument product standard should state whether each immunity test result is required to be a Class A, Class B or Class C item. The test report should include the test conditions and test results. Table 1 Radiated oscillation disturbance source and disturbance range 9 kHz~A (controlled) x (severe) 27 MHz, any 27 MHz band, CB (civilian frequency amateur radio, all bands 27 MHz~1 000 MHz portable, CB except mobile, CB except Consider item by item according to equipment requirements Consider item by item according to situation 27 MHz~1 000 MHz Unit is V/m 1 000 MHz~40 GHz. Except for CB, portable and mobile. Note: For typical waveforms of radiated oscillation disturbance and calculated values ​​of field strength at different distances for various sources of certain transmission power, see Appendix A. Table 2 Disturbance degree of continuous wave voltage induced relative to reference ground Disturbance degree A (controlled) X (severe) (10~150)kHz (0.15 ~~27)MHz
Consider each item according to the equipment requirements
Consider each item according to the situation
(27 ~~ 150)MHz
Note 1: This interference refers to the induced voltage relative to the reference ground generated when the wire is exposed to the electromagnetic field. The amplitude of the induced voltage depends on the length of the wire, the height from the ground, the loop formed by stray capacitance and other equipment, etc. Note 2: The table gives the calculated values ​​of the induced voltage and the corresponding common-mode current, assuming that the characteristic impedance to the reference ground is 150Ω (the common-mode impedance of the power grid may be much less than 150Ω).
Note 3: The disturbance degree in the table is under unmodulated conditions. The disturbance signal that usually appears is amplitude modulated (typically less than 80% modulation) or frequency modulated. Some very low frequency (VLF) transmitters can induce higher voltages in the (10~150)Hz frequency band. 4
Disturbance level
A(controlled)
X(harsh)
Table 3 Disturbance sources and disturbance levels of low (industrial) frequency magnetic fields Power frequency 50Hz/60Hz
Consider item by item according to equipment requirements
Consider item by item according to circumstances
GB/T11684—2003
Unit: A/m, rms
Note: For overhead lines, measure at 1m above the ground. Below the center of the line, the magnetic field amplitude has a range. For home and commercial environments, measure at 0.3m from the source, and the magnetic field amplitude range is (1~10)A/m. Table 4 Sources of electrostatic discharge and range of disturbance degree
Electrostatic discharge source
Rise time
Occurrence rate
Occurrence frequency
Source impedance—resistive
——capacitive
Characteristic quantity and disturbance degree
A (controlled)
X (severe)
Depends on the number of people on site
(100~~500)Q
(100~500)pFb||tt ||Rate of rise of discharge current/
Charged voltage before discharge/
Depends on the number of people on site
(100～500)0°
(100～500)pFb
Rate of rise of discharge current/
Consider item by item according to equipment requirements
Consider item by item according to the situation
Charged voltage before discharge/
Note: Electrostatic discharge occurs when a charged person or object approaches another person or object. The electrostatic discharge receptor is first subjected to the electric field generated by the charge, and then when dielectric breakdown occurs, it is accompanied by transient current discharge with complex characteristics and generates a transient electromagnetic field. Depends on different sources: hand-held tools, bare hands, objects. b Depends on the insulation of the personnel or the size of the object. 5
GB/T 11684--2003
Disturbance degree
A (controlled environment)
x ​​(harsh)
Table 5 Disturbance sources and disturbance degree range of voltage amplitude and frequency of power supply system
Fluctuation relative to normal working voltage
Duration of voltage sag b (30%U.
and 60%U.)
Duration of short interruption h (99%
Consider item by item according to equipment requirements
(400～800)ms and
(0~~400) ms
(1. 5~3) s and
(0. 8~1. 5) s
<600ms
Consider item by item according to the situation
Relative to the normal working frequency
Fluctuation/%
The main interference sources are industrial loads such as arc furnaces (high voltage network), electric welding machines (low voltage network), capacitor banks and the switching of large loads. b
The main disturbance sources are the action of fuses for short circuits in the low voltage network (a few milliseconds), faults in medium and high voltage lines or other equipment, with or without automatic reclosing (100 ms~600 ms), and the switching of large loads, especially motors and capacitor banks. Table 6 Unidirectional transient sources and disturbance degree ranges conducted in low voltage AC power supply systems Phenomenon attributes and
Typical sources
Rise time.
Duration:
Occurrence rate
Event duration.
Source impedance
A (controlled environment)
X (harsh)
Contact arc.
Burst (pulse group)
One-way transient time scale
Lightning <1km2
(1～10) 2
Lightning >1km2
10 μs
1000us
(20300)Q
Consider each item according to equipment requirements
Consider each item according to the situation
Fuse action
(0.2～2) Q
The values ​​shown are the open circuit voltage of the (120～690)V (RMS) power system (that is, when the phenomenon occurs, there is no large load connected to the system and no surge protection device installed). They reflect the external source and coupling mechanism of these transients and are independent of the system voltage. The current is the current carried by the power lines in the building, not the external lightning current. A direct lightning strike to a building will generate a large current in the power line.
The value shown is the open circuit voltage when a transient occurs at the peak of the power frequency sine wave, and is added to the power frequency voltage. These transients are generated by internal sources and are basically proportional to the system voltage (Upeak).
The initial rise time of the transient.
The width at half peak of a single transient.
The order of magnitude of the total duration of multiple transient events, expressed in the units shown. 6
Characteristic quantities of electromagnetic phenomena
and disturbance degree
Typical source
Rise time.
Duration
Occurrence rate
Source impedance
A (controlled)
x ​​(severe)
Table 7 Transient sources and disturbance degree ranges of conducted oscillations in low-voltage AC power supply systems Ringing wave transient frequency range
High frequency (0.5~～5) MHz
Response of local system to pulse disturbance
(50～300)
Medium frequency (5～500) kHz
Response of building to pulse disturbance
20 μs
(10～50) 2
Consider item by item according to equipment requirements
Consider item by item according to the situation
GB/T 11684—-2003
Low frequency (0.2~5)kHz
Capacitor switching b
Not often
(10~50)n
The values ​​shown are the open circuit voltages for a (120~690)V (rms) power system (i.e., when the phenomenon occurs, there is no large load connected to the system and no surge protection device installed). They reflect the external sources and coupling mechanisms of these transient voltages and are basically independent of the system voltage. The values ​​shown in
are the open circuit voltages when transients occur at the peak of the power frequency sine wave, including the power frequency voltage. These transients are generated by internal sources and are basically proportional to the system voltage (U#).
The initial rise time of the transient.
The width of the half peak of the transient envelope.
GB/T 11684—2003
Electromagnetic disturbance
Population and other
Rural residential areas may be representative of such
locations.
Typical locations
Not under high-voltage lines;
distance to radio broadcast transmitters greater than 1 km;
distance to amateur radio stations greater than
Overhead lines;
areas exposed to strong lightning flashes; high network impedance.
AC power supply
DC power supply
Signal and control
Examples of typical
nuclear instruments working in various locations
Not applicable.
Overhead communication cables or lines;
Short control lines, less than
10 m; exposed to strong lightning flash areas.
Connection to overhead network; Local grounding with or without high impedance; Grounding of multiple local grounds without connection.
Radioactive prospecting instruments, radiation protection instruments, some environmental monitoring
Table 8 Electromagnetic environment of nuclear instruments
Exposure to medium lightning flash areas; High and user system connection; No light industrial area may be this type of location. The line may pass through the building with manufacturing or machinery plants. Above.
Commercial areas are
representatives of this type of location.
Urban residential areas may be representatives of this type of location.
Distance to amateur radio stations
>20 m; distance to radio broadcast transmitters
operating below
>5 km; high-frequency
electrotherapy equipment may be present; local
substations may be near; audio/aided listening systems may be present in public places.
Cables or short overhead
Not applicable.
Cables or short overhead
Massive metal structures, which may or may not be shielded and earthed, or
earthed.
Some place monitoring instruments and environmental monitoring instruments (such as radiation level instruments (such as hydrogen and its progeny monitoring instruments).
Note: The electromagnetic environment location category of each type of nuclear instrument should be stated in the manual. 9
Representative of the location.
Distance from amateur radio stations is greater than 20m;
Distance from radio broadcast transmitters operating below 1.6 MHz is greater than 5km;
paging and portable communication systems;
information technology
equipment (ITE) is highly concentrated;
there may be high-frequency electrotherapy equipment;
may be close to the local substation;
there may be audio/hearing aid
systems.
Cables or short overhead lines; high harmonic levels of information technology equipment (ITE), lighting, adjustable speed drive (ASD) systems; equipment mounted on roofs (exposed to lightning strikes).
Not applicable.
More than 5km; paging and portable communication systems; high concentration of information technology equipment (ITE);
May be near low-power industrial, scientific and medical equipment (ISM); may have high-frequency electrotherapy equipment; may be near local substations; may have audio/|tt||aided hearing systems.
Cables or short overhead spans.
Not applicable.
Cables or shorter overhead cables or shorter overhead distances; signal systems and the operated
power systems are closely coupled.
A large number of metal structures, which may be
(or not) shielded and grounded, or
grounded; common
connections between power systems and
telecommunications (including local) systems.
Certain medical nuclear instruments, certain
a large number of metal structures, which may be
(or not) shielded and grounded, or
grounded.
Certain isotope and radiation applications
Isotope and radiation applications nuclear
Nuclear instruments. Certain containers, etc.
Instruments.
Non-destructive testing radioactive source applications or
accelerator applications nuclear instruments.
Place categories and characteristics
GB/T 11684—2003
Communication center may be a heavy industrial area with magnetic resonance imaging equipment, a power plant or a switch station. Applicable to fixed facilities. Traffic areas may be representatives of this type of location. May be representatives of this type of location.
Representative.
Distance to amateur radio stations
Parking lot under high-voltage lines; close to
High-power mobile transmitters.
More than 20 m; 1.The distance of radio broadcast transmitters operating at 6 MHz and below is greater than 5 km; close to high-power industrial, scientific and medical equipment (ISM); close to medium-voltage and high-voltage power system operation and isolation equipment; handheld transmitters and paging systems with high probability of operation; close to arc welding machines; near medium-voltage cables. Underground cables of medium-sized power plants; large overhead lines; exposed to lightning strikes. Dedicated high-voltage substations of medium-sized power plants; may be dedicated feeders; may be correction of inherent power factor of self-generated power generation; large adjustable speed drive (ASD) systems; operation of disconnectors; arc furnaces; large inrush loads; may have large fault currents.
Rectifier with battery; inductive operation is not applicable. Load, large inrush current load.
Widely existing lines, can be isolated in power plants; may have cable
pipeline routing; may be closely coupled to power switch
devices; exposed to outdoor; exposed to increased lightning flash zone.
Extensive connection to the network; large-area grounding grid, generally well controlled; interconnected decentralized grounding grid; large grounding rings, may have large ground fault currents.
Reactor nuclear instrumentation, radiation protection instrumentation
site monitoring, effluent monitoring
and personal monitoring instruments, some isotope application detection instruments.
Exposure to lightning flash zone.
Long lines with different reference grounds.
Intentional building shielding may be used;
Use of portable transmitters may be prohibited;
Electrostatic discharge (ESD) mitigation measures may be used.
Cables or short overhead lines: High harmonic wave levels (ITE, lighting, ASD);Www.bzxZ.net
Equipment mounted on rooftops (lightning exposure).
Some areas will have high DC
and low angular magnetic fields.
Pulsed lasers and surgical knives may be present in some areas.
Hospitals may be representative of such locations.
Close to low-power industrial, scientific and medical (ISM) equipment: X-ray pulses and internal flashovers (arcing) in X-ray tubes High-frequency electrotherapy equipment: linear accelerators (magnetron breakdown in the GHz frequency range); ultrasonic wave equipment (MHz electric pulses).
Life-saving equipment; isolation transformers, uninterruptible power supplies; backup generators.
Special rectifiers with batteries (may be
Not applicable.
Backup); may be backup generators.
Protection of signal systems and operated power systems against lightning strikes on lines without lightning arresters; close coupling between electrostatic discharge systems; low-level monitoring (ESD) mitigation measures.
Good practice for control.
Visual systems.
Control well grounding (safety) habits.
"Some environmental monitoring radiation protection [some medical nuclear instruments. Some containers and other non-destructive testing radiation source application or accelerator application nuclear "instruments. Instruments.
GB/T 11684-2003
Electromagnetic phenomena (sources) and characteristic quantities
9kHz~27MHzAny source
27MHz (civilian frequency band) (CB)
High (radio) frequency
Radiated oscillation
(Table 1)
High (radio) frequency
Conduction induction
Continuous wave
(Table 2)
Low (industrial) frequency
(Table 3)
Electrostatic discharge
(Table 4)||t t||Low frequency conduction
(Table 5)
High frequency conduction
One-way transient
(Table 6)
Conducted oscillation
(Table 7)
Amateur radio, full band
(27～1000)MHz portable, except CB(27～1000)MHz mobile, except CB
(27～1000)MHz All other sources
(1～40)GHz All sources
(10～150) kHz
(0. 1-~30) MHz
(30～150）MHz
Power frequency 50Hz/60Hz
Power voltage fluctuation
Power voltage drop
Power short-term interruption
Power frequency change
Microsecond, close distance
Microsecond, long distance
Transient frequency high frequency
Transient frequency medium frequency
Transient frequency low frequency
Note: E: Shell, AC. Alternating current power supply, DC: Direct current power supply, C/S: Signal and control, G: Ground. 10
Table 9 Nuclear instrument electromagnetic environment various places
Place category and
Dcjc/s
DCC/SG
GB/T 11684--2003
Classification of disturbance sources and disturbance levels
Disturbance levels
DCIC/S
ACDCC/S
AC|DCC/S
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