I.S. CLC TR 50427:2005
Current
The latest, up-to-date edition.
ASSESSMENT OF INADVERTENT IGNITION OF FLAMMABLE ATMOSPHERES BY RADIO-FREQUENCY RADIATION - GUIDE
Hardcopy , PDF
English
01-01-2005
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and abbreviations
4.1 Modulation codes
4.2 Polarization codes
5 General considerations
5.1 Radio-frequency hazard
5.2 Philosophy of systematic method of approach
5.3 Responsibility for making the hazard assessment
6 Transmitters and transmitter output parameters
6.1 Types of transmitter
6.2 Frequency range
6.3 Transmitter output power
6.4 Antenna gain
6.5 Modulation factors
6.5.1 General
6.5.2 Frequency modulation (FM)
6.5.3 Amplitude modulation (AM)
6.5.4 Single sideband (SSB) operation
6.5.5 Pulsed radar
7 Structures and spark-making mechanisms
7.1 Structures
7.2 Loop-type structures
7.3 Vertical structures
7.4 Spark-making mechanisms
8 Ignition of flammable atmospheres
8.1 Flammable atmospheres
8.1 Flammable atmospheres
8.2 Ignition by radio-frequency discharges
8.3 Criteria for ignition
8.3.1 Effectively continuous transmissions
8.3.2 Radar transmissions
9 Practical measurements and tests
9.1 Measurement of electromagnetic fields
9.2 Measurement of extractable power
9.3 Test transmissions
9.4 Incendivity tests
10 Methods of assessment for determining potential RF ignition
hazards on a plant containing hazardous areas
10.1 General
10.2 Basis of the theoretical assessments
10.2.1 General
10.2.2 Initial assessment
10.2.3 Full assessment
10.3 Initial assessments
10.3.1 Initial assessment of the risk from a particular
transmitter site
10.3.2 Initial assessment for a particular plant
10.4 Full assessment procedure
10.4.1 Procedure
10.4.2 Information to be obtained
10.4.3 Calculation of effective field strengths
10.4.4 Calculation of extractable power or energy
10.4.5 Comparison of the total extractable power or
energy from the structure with the threshold
values detailed in Clause 8
10.5 Practical on-site tests
10.5.1 Procedure
10.5.2 Plant and transmitter both in existence
10.5.3 Existing plant and proposed transmitter
10.5.4 Existing transmitter and proposed plant
11 Plant safety measures
11.1 General
11.2 Bonding
11.3 Insulation
11.4 Reducing the structure efficiency
11.5 De-tuning of structures
12 Special cases
12.1 Cranes
12.2 Mobile and portable transmitters
12.3 Ships
12.3.1 General
12.3.2 Ships in harbour areas
12.3.3 Ships at sea
12.4 Offshore oil and gas installations
12.4.1 General
12.4.2 Structures on offshore installations
12.4.3 Assessment procedures
12.4.4 Radio frequency transmitters and vulnerable zones
12.4.5 Safety measures and recommendation
Annex A (informative) Sources of information and addresses of
some advisory bodies
Annex B (informative) Electromagnetic radiated fields and
examples of radiating antenna and
unintended receiving antenna characteristics
Annex C (informative) Subdivision of group II flammable gases
and vapours
Annex D (normative) Measurement of electromagnetic fields
Annex E (normative) Methods of measurement on structures
(on-site tests)
Annex F (informative) Derivation of vulnerable zone distances
for Table 5, Table 6 and Table 10
Annex G (informative) Worked examples of full assessment procedure
Annex H (informative) Ground-wave propagation (vertical polarization) -
Calculation of field strength
Bibliography
Defines guidance on assessing the potential ignition hazard from the inadvertent extraction of energy from electromagnetic fields, propagated from communication, radar or other transmitting antennas to plant where a potentially flammable atmosphere may be present.
DocumentType |
Standard
|
Pages |
97
|
PublisherName |
National Standards Authority of Ireland
|
Status |
Current
|
Standards | Relationship |
CLC/TR 50427:2004 | Identical |
IEC 60079-10:2002 | Electrical apparatus for explosive gas atmospheres - Part 10: Classification of hazardous areas |
EN 60079-0:2012/A11:2013 | EXPLOSIVE ATMOSPHERES - PART 0: EQUIPMENT - GENERAL REQUIREMENTS (IEC 60079-0:2011, MODIFIED) |
EN 50020:2002 | Electrical apparatus for potentially explosive atmospheres - Intrinsic safety 'i' |
CLC/TR 50426:2004 | Assessment of inadvertent initiation of bridge wire electro-explosive devices by radio-frequency radiation - Guide |
IEC 60079-0:2011 | Explosive atmospheres - Part 0: Equipment - General requirements |
EN 60079-10:2003 | Electrical apparatus for explosive gas atmospheres - Part 10: Classification of hazardous areas |
EN 60215 : 89 AMD 2 94 | SAFETY REQUIREMENTS FOR RADIO TRANSMITTING EQUIPMENT |
EN 50014:1997/A2:1999 | ELECTRICAL APPARATUS FOR POTENTIALLY EXPLOSIVE ATMOSPHERES - GENERAL REQUIREMENTS |
CISPR 16-1:1999+AMD1:2002 CSV | Specification for radio disturbance and immunity measuring apparatus and methods - Part 1: Radio disturbance and immunity measuring apparatus |
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