Table 5-l.
Coefficients
for magnetic field
c2
loss*
Units for distance (t)
Coefficient
5
reflection
Inches
Mils
Meters
Millimeters
0.0117
11.7000
0.462
462
5.350
0.0053
0.136
136
H. W. Denny, et al., Grounding, Bonding, and Shielding Practices and Procedures for Electronic Equipments and Facilities, Vol I-II, Fundamental Considerations, Report No. FAA-RD-75-215, I (Engineering Experiment Station, Georgia Institute of Technology, December 1975).
*Source:
5-69
I:
I
! .!%
/
,
Table
:!
!
!
I
‘i.‘,
::
O.b
,90
Steel
60
58
Al
60
48
46
Al
31
35
45
--
--
Al
20 (diem)
55
36
--
--
22 12 16
CU CU
20 (diam)
SO
--
no.
10
uo.
4
Mono1 Celveired eteel
76
--
diem,
Yo. 16 16 x 16/eq No. no. No.
in.
65 45
Br0n;.
18 (diem) 30 (diem) 28
(14
kH; SO (14 UIr 40 35
-
60 !IYz)
-
60 NYz)
(14
- NH;)
MO. 2
*Source:
materials
Op=n area, in. of weter 200 Cu ft/mio
lffectiveneer to 1000 I#;),
dB
3
9-mil holee, 28-mil centera
Herb (screening)
Yominel (14 ur
Al
N shadow urt (photoetched)
Perforeted rhcct
Thickneee, milr
shielding
1. 6. khulte, Capecibiliry (KInI,
lt l I., “Ibieidinl Ore&w 1973).
meOrt
end Prectice,I’
wir 24
Proceedings
--
08 of the Tri-Service
Conference
on Elrctronurnctic
Table 5-16.
Test type
Magnetic field (r = 1.75
Plane
wave
Electric
Comparison of measured and calculated values of shielding effectiveness for No. 22, 15-mil copper screens*
Frequency, MHz
in.)
Measured effectiveness, dB
Calculated effectiveness, dB
0.085 1 .ooo 10.000
31 43 43
29 46 49
0.200 1 .ooo 5.000 100 .ooo
118 106 100 80
124 110 95 70
0.014
65
65
field *Source: W. Jarva, “Shielding Efficiency Calculation Methods for Screening, and Other Perforated Electromagnetic Shields,” Waveguide Ventilation Panels, Proceedings of the Seventh Conference on Radio Interference Reduction and Electromagnetic Compatibility (IITRI, November 1961).
5-86
Table 5-17.
Bar diameter, cm
5.8 4.3 2.5 5.8 4.3 2.5 *Source : 1977).
Attenuation
factors
for reinforcement
steel
construction*
Bar spacing, cm
Type of construction
Attenuation decrement, AdB
30 35 45 50 35 40
Single-course Single-course Single-course Double-course Double-course Double-course
+5 0 -6 +8.5 +13 +5
EMP Engineering Practices Handbook, NATO File No. 1460-2 (October
5-87
I
Table 5-18.
Application
factors
Wire diameter, mm
Spacing, cm
3 3
20 20
*Source: 1977).
EMPEngineering
for welded wire fabric*
Number of courses
1 2
Practices
Attenuation increment, dB -3 +4
Handbook, NATOFile No. 1460-2 (October
5-88
Table
5-19.
Typical
values
of conductivity
for soils
and rock*
Geological period and rock type
Electrical conductivity, mho/meter
1x10-l
Quaternary tertiary Quaternary
Shallow playa depoei ts
yl 20
cretaceous
Loam, clay
Jurassic triassic carboniferous
we
Devonian Silurian Ordovician Cambrian
--
3x1o-2
Chalk
Chalk, trap
--
1x1o-2
Alluvium
Alt. basalt, shale
--
Limestone, sandstone
Shale, 1 imes tone
W
3x10-3
lr10-3
3x10-4 to 1x10-4
*Source:
Coarse
sand
--
--
Cambrian Precambrian
Sandstone, dolemi te
Sandstone
--
Quartzite, slate, granite, gneiss
and gravel in surface layers EliP Engineering Practices Handbook, NATO File No. 1460-2 (October 1977).
7. 7. ::; .- .-i .r.._ _:. .;-. -_, ._ ..
/
!
!’ ”
!
! / i
/ /I?,
t
.:. ‘..!‘I
Table 5-20.
/
Skin depth (d) and absorption
loss
(A) for
Water content
6(m)
1 kHz 10 100 300 1 3 10 100
kHz kHz kHz MHz MHZ MHZ MHz
*Source: 1977).
A(dB/m)
0 0
950
280 80 40 18 8.7 3.5 0.56
(%I
10
1
Frequency
nonmetal materials*
0.1 0.2 0.5 1.0 2.5 15.6
EMP Engineering Calculated using
s(m) 172 53 16 9 4.9 2.7 1.3 0.28
50 A(dB/m) 0.1 0.2 0.5 0.9 1.8 3.2 6.7 31.2
Practices Handbook, NATO File infinite-plane geometry.
5-90
6(m) 50 .I6
5 2.8 1.5 0.87 0.46 0.12
No.
1460-2
A(dB/m) 0.2 0.5 1.7 3.0 5.6 9.9 18.7 68.5 (October
Table 5-21.
Electromotive series
Element
vorts
Lithium Rubidium Potassium Strontium Barium Calcium Sodium Magnesium Aluminum Beryllium Uranium Manganese Tellurium Zinc Chromium Sulfur Gallium Iron Cadmium Indium Thallium Cobalt Nickel
2.9595 2.9259 2.9241 2.92 2.90 2.87 2.7146 2.40 1.70 1.69 1.40 1.10 0.827 0.7618 0.557 0.51 0.50 0.441 0.401 0.336 0.330 0.278 0.231
Ion
Fe++
Element
Volts
Tin Lead Iron Hydrogen Antimony Bismuth Arsenic Copper Oxygen Polonium Copper Iodine Tellurium Silver Mercury Lead Palladium Platinum Bromine Chlorine Gold Gold Fluorine
0.136 0.122 0.045 0.000 -0.10 -0.226 -0.30 -0.344 -0.397 -0.40 -0.470 -0.5345 -0.558 -0.7978 -0.7986 -0.80 -0.820 -0.863 -1.0648 -1.3583 -1.360 -1.50 -1.90
5-91
Ion
Pb::+
Fe
cu++ cu+ Te
Pb
++++
++++
++++ Au Au+
1::’
F:’
.‘.I.
1
‘I
,
1
:t
