A
unique probe
The AL-40 is equipped with a probe designed specifically for
aluminothermic welding, and that uses the four-points measuring
method. This technique consists of injecting a known current through
two current contacts, then to measure the voltage with the help of
two voltage contacts placed in between. The current is read as well,
to eliminate the contact-resistance factor.
The instrument is also equipped with a microprocessor that
eliminates offsets and parasite voltages.
Thanks to its unique filtering system, the AL-40 can be used in
presence of intense magnetic fields.
Quality
control of aluminothermic welding
The quality of energy and grounding networks joints is of prime
importance for the companies who produce or use high power electric
energy (power plants, substations, railways, aluminum foundries,
etc). A bad quality joint provocates a decay of the network’s
performances, that soon translates into excess of maintenance. The
traditional method to check aluminothermic welding used to be a
visual inspection, but this method is now considered ineffective
because a lot of factors escape to this type of control: conductors oxidation,
insufficient preheating temperature or traces of humidity can all
result in a solid, good looking welding which resistance value is
still too high.
Measuring the resistance value of such welding with the AL-40
enables you to make the difference.