Product Manual

4
Figure 1 – cross section view of a cable crimped in
connector
Data transfer rate
An important aspect of a cable is its data transfer
rate. The data transfer rate depends on the quality
and design of the cable.
Cables are designed to achieve the data transfer
rates required for the intended purpose and field of
application so that the user does not lose time as a
result of slow data transfer.
Figure 2 – table showing different speeds USB connections
Figure 3 - The figure shows a typical eye diagram used to
assess whether the desired data transfer rate has been
achieved.
Environmental specifications
and fields of use
The cables undergo special tests during the design
phase and regularly afterwards in order to ensure
that they can meet the high demands placed upon
them. For example, they are tested to see whether
antikink protection and flexibility is retained at very
low temperatures and that fracture or embrittlement
does not occur. All Leica cables are tested for the
protection they provide against splash water, high
humidity and condensation. The materials must be
able to resist UV light for many years and withstand
extreme temperature shocks, survive vibrations and
drop tests, and be resistant to lime, sand and
cleaning agents. High barometric pressures, such as
at depths of -1000 m or at an altitude of 8500 m,
have no effects on original Leica accessories.
Regulations and guidelines
Leica Geosystems would like to set the standard and
an example for the future by having its cables fulfill
all applicable and recommended regulations.
The following rules, regulations and directives are
currently considered in the design of Leica
Geosystems cables.
PAH – polycyclic aromatic
hydrocarbons
Only very few people are aware that the German
Federal Institute for Risk Assessment (BfR) issued a
new guidance document in 2008 that limits an
article's percentage content of polycyclic aromatic
hydrocarbons. Many PAH compounds used in the
plastic used to make the outer jacket of cables are
proven carcinogens.
Some PAH compounds have been clearly shown to be
carcinogenic to humans (e.g. causing cancer of the
lungs, larynx, skin, stomach, intestines, and bladder).
They are also associated with birth defects and
reduced reproductive capacity.
These compounds can be absorbed by skin contact,
for example through the hands.
The guidance document sets out the permitted limit
for the amount of PAH absorbed through the skin
over a specific period of time.