During the first half of the 20th century, while most technologies focussed on the minimisation of this loss, some companies in Europe started to produce components which could transform into heat all the electricity that crossed them, the Electric Heaters.
Early Days and Company Evolution
Design and Production
In particular, a GROUP II area is a surface environment (not a mine) in which there is the presence of potentially explosive gas and / or dust. The GROUP I areas are the mines with the presence of grisou gas.
Masterwatt heaters are suitable for working in areas classified as GROUP II