Förbättrad resistansmätning för grova aluminiumledare
The goal with this master thesis has been to evaluate and to examine the
stationary resistance bridge. The resistance bridge uses a 4-point measuring to
determinate the resistance, which is used in the manufacturing of the
conductor. It is then used when the resistance is to be decided for coarser
aluminium conductors. A conductor has to fulfil certain demands to be able to
move forward in the process. One of these demands is the resistance in ohm/km,
which has demands that the measure values of the resistance bridge are as true
and precise as possible.
The stationary resistance bridge had been examined through various kinds of
measurements to be able to see how stable the system is and how to obtain a
measure value as optimized as possible. The measurements were carried out in
different dimensions and types of aluminium conductors, and in each measurement
a various different tests were carried out for the aluminium conductor. The
result of the measurements shows that the system is not stable for aluminium
conductors with a cross-section area more than ~1000 mm2. This depends on that
current in the resistance bridge does not distribute it self even in the whole
conductors cross-section area. The distribution of the power has improved by
using contact pressing and brings a more stable measure value. Another method
will however be necessary to be able to decide the resistance in ohm/km for the
aluminium conductors with swelling powder and swelling tape.