TWI Frequently asked questions
Video systems can be used. If the space available for the camera is small, then it may be necessary to use a fibre optic system between the lens and the camera. This comprises a lens which focuses the image of the arc onto a fibreoptic which would then transmit the image to a camera / monitor at a more convenient location.
For good pictures, it is important to use good quality optical (rather than TV) lenses.
Neutral density filters are used to reduce the arc light intensity so that the operator can view the welding process. It is usually necessary to remove the filter and to provide auxillary light to view the joint / weld bead whenthere is no arc.
Recently, graded neutral density filters have been developed with strong filtering where the arc is and less dense in the surroundings. When these filters are used, the direction of focusing is important.
It is possible to build such a monitoring system based on home video equipment.
Copyright by TWI, 1999
