Method to Assess Magnetic Fields From Welding Against the EU-Directive on Electromagnetic Fields
Paper i proceeding, 2014
The EU Directive 2013/35/EU, which will be enforced in all member states July 1st 2016, requires that companies carry out a risk assessment for workers exposure to Electromagnetic fields (EMF). EMF:s are created by electric voltages and currents.
Large current are used in welding, which gives rise to high magnetic fields, this means that the worker exposure has to be assessed against the limits.
The exposure limit values are expressed as the induced electric field strength in the human body. The induced electric field cannot be measured, only calculated in computer simulations. Therefore the directive also gives action levels expressed in the magnetic field strength, which can be measured.
The magnetic fields in welding are often not sinusoidal and for that reason, the waveform of the welding current has to be assessed; this can be done using a technique called weighting filters. If the action levels are exceeded, an assessment against the exposure limit values has to be done.
An assessment of welding exposure to EMF can be quite complex and costly. To facilitate this assessment, software has been developed in the EU EMFWELD project.