PD CLC/TR 50426:2004

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 hazards
   5.2 Philosophy of the systematic method of approach
   5.3 Responsibility for the making the hazard assessment
   5.4 Recommended practices for radio silence in offshore
       operations
6 Transmitters and transmitter output parameters
   6.1 Types of transmitters
   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 Circuits for blasting and well perforation
   7.1 General
   7.2 Typical blasting circuit layouts
       7.2.1 General
       7.2.2 Extended line blasts
       7.2.3 Benching or 3-dimensional blasts
       7.2.4 Multipattern blasts
       7.2.5 Shaft sinking
       7.2.6 Demolition work
   7.3 Circuits formed during well-perforating using wireline
8 Electro-explosive devices
   8.1 General
   8.2 Commercial EED
   8.3 EED hazard threshold
   8.4 Common mode operation
9 Methods of assessment for determining potential RF ignition
  hazards on a site where EED are used
   9.1 General
   9.2 Basis of the theoretical assessment for land sites
       9.2.1 General
   9.3 Initial assessment for land sites
       9.3.1 Initial assessment of the risk from a particular
             transmitter site
       9.3.2 Initial assessment for a particular site using EED
   9.4 Full assessment procedure for land sites
       9.4.1 Procedure
       9.4.2 Information to be obtained
       9.4.3 Calculation of effective field strength
   9.5 Safe field strength
       9.5.1 General
       9.5.2 Single EED
       9.5.3 Single EED with extended leading wires
       9.5.4 EED in typical quarry/demolition firing circuits
       9.5.5 EED in well-perforating drilling operations
   9.6 Multiple transmissions
       9.6.1 General
       9.6.2 Multiple-transmission assessment for
             quarry/demolition sites
       9.6.3 Multiple-transmission assessment for
             well-perorating drilling operations
   9.7 Assessment for offshore drilling operations
10 Practical on-site testing
11 Safety procedures
   11.1 General procedures
   11.2 Alternatives means of firing
12 Special applications
   12.1 Semi-permanent installations
   12.2 Flammable hazard of situations
   12.3 Use of transmitters in mines and quarries
   12.4 Safety in transit
Annex A (informative) Extraction of energy from the
        electromagnetic field
Annex B (informative) Measurement of electromagnetic fields
Annex C (informative) Sources of information and address of
        advisory bodies - UK ONLY
Annex D (informative) Electromagnetic radiated fields and
        examples of radiating antennas and unintended receiving
        antenna characteristics
Annex E (informative) The effective resistance of the leading
        wires of an EED
Annex F (informative) Derivation of minimum distances of safe
        approach for Table 2 and Table 3
Annex G (informative) Ground-wave propagation (vertical
        polarization): calculation of field strength
Annex H (informative) Worked examples to demonstrate the effects
        of antenna gain
Annex I (informative) The effects of leading wire resistance,
        safely resistors and the use of EED with different
        characteristics
Annex J (informative) Derivation of Figure 12a) to Figure 12g)
        for EED alone incorporating the resistance of leading
        wires and safety resistances
Bibliography

Presents guidance on assessing the possibility of inadvertent extraction of energy from an electromagnetic field propagated from radio frequency (RF), radar or other transmitter antennas and the coupling of this energy to an electro-explosive device (EED) in a manner capable of causing initiation.

This European Technical Report provides guidance on assessing the possibility of inadvertent extraction of energy from an electromagnetic field propagated from radio frequency (RF), radar or other transmitter antennas and the coupling of this energy to an electro-explosive device (EED) in a manner capable of causing initiation. The frequency range covered by this European Technical Report is 9 kHz to 60 GHz. This European Technical Report only applies to bridge-wire devices which are directly initiated by radio frequency current and does not apply to special detonators, for example, electronic detonators. It does not cover the similar hazard arising from electromagnetic fields generated by other means, for example electric storms, electricity generating plant or power transmission lines.

This European Technical Report does not apply to the following equipment:

• air bag igniters for automotive applications (including the igniters before they are fitted);

• special pyrotechnic devices;

• pyromechanisms;

• igniters for fireworks;

• special military devices;

• special safety equipment.

NOTE The methods of assessment from 9 GHz to 60 GHz are based on extrapolation of data for frequencies below 9 GHz.