19
Prefixes to the unit:
Designation
Unit
Factor
Is the equivalent of
Hertz
Hz
1
1 Hz
Kilohertz
kHz
10³
1000 Hz
Megahertz
MHz
10
6
1000 000 Hz
Gigahertz
GHz
10
9
1000 000 000 Hz
Terahertz
THz
10
12
1000 000 000 000 Hz
16.3 Signal strength / absorption
The signal strength is reduced by materials on the transmission path between the transmitter and receiver. This is known
as signal attenuation. The degree of attenuation is greatly dependent on the type, thickness and density of the material.
Material
Penetration
Example
Wood / wood with plasterboard
Very good
Internal partitions
Plastic
Very good
Plastic windows
Glass normal, metallised
Good
Window panes
Bricks
Average
External wall
Water
Average
People, aquariums
Concrete with steel reinforcements
Poor
Solid walls
Metal
Very poor
Fire doors
Additional attenuation from the following may also have to be taken into consideration:
•
Installation of wireless components in a flush-mounted socket
•
Metal coatings, e.g. on furniture and wall coverings
•
Planted areas
•
High air humidity