BS G 257-1:1998

Committees responsible
Foreword
1 Scope
2 Informative references
3 Definition
4 Background
5 Basic principles of EMH protection design
6 EM hazards
Table
1 Current component
Figures
1 Magnetic field at a point distant from a current element
2 Interaction of magnetic field with conducting loop
3 The summation of magnetic field around a closed loop
4 Concept of displacement current
5 A wave in space
6 A wave f (x,t) in time
7 A wave f (x,t) in space
8 A sinusoidally periodic wave
9 Exponential decay of signal with position
10 A standing wave
11 An EM wave propagating in the x-direction
12 The components of an elliptically polarized wave
13 A short dipole in cartesion co-ordinates
14 Antenna types
15 Wave propagation in three media
16 Plane wave incident on a cylinder
17 The current distribution on a cylindrical body
18 Current crowding at corners
19 Shielding effectiveness of spherical shells
20 Typical shield imperfections
21 Penetration through an aperture
22 Penetration through a low conductivity panel
23 The mechanism of shielding reduction by a penetrating
    conductor
24 A short circuit observed down a transmission line
25 An open circuit observed down a transmission line
26 The development of a dipole from an open-circuit
    transmission line
27 Current and field distribution in coaxial cable
28 H-field coupling and common-mode interference
29 Long-tailed pair with common-mode current rejection
30 Filter installation
31 Typical high-frequency equivalent circuit of a motor
32 Transformation of pulse into the frequency domain
33 Possible intersystem coupling paths
34 Model of a severe negative lightning flash current
    waveform
35 Model of a moderate positive lightning flash current
    waveform
36 Intra- and inter-cloud, multiple burst current waveforms
37 Pre-strike electric field voltage waveforms
38 Current component A
39 Current component Ah
40 Current component B
41 Current component C
42 Current component D
43 Multiple stroke
44 External idealized current component H
45 Double exponential current waveform I
46 Double exponential derivative voltage waveform 2
47 Damped sinusoidal voltage/current waveform 3
48 Double exponential voltage waveform 4
49 Double exponential current waveform 5
List of references

Identifies design and development practice that should optimise airframe and system protection, and minimize the cost, weight and volume penalties of providing protection.

This Part of BS G 257 has been written to assist engineers working at all levels within companies involved in the aircraft industry. The guide does not contain mandatory requirements, but rather advice to assist in the solution of design problems. In order to meet the EMH protection needs of the customer\'s specification, it is strongly recommended that engineers consider the features discussed and use the suggestions made or provide an alternative solution for any problem.

This guide does not discuss the following:

1. the protection of the airframe against the structurally damaging, direct effects of lightning;
2. the design of communication systems in order to produce interference-free operation, since these aspects of RF systems design are covered in adequate detail in other documents; however, the problems of interaction between radio receivers and transmitters remain an important class of electromagnetic compatibility (EMC) problem.