scope:

Scope of application

The technical bulletin deals exclusively with sensors which, according to their working principle, can be utilised for fully mechanised arc welding (search for the start of the groove and/or groove tracking) and serve to position the electrode relative to the welding groove and, if necessary, to regulate the welding parameters. Part 1 of this technical bulletin includes a representation of the physical working principles of various sensors. Part 2 considers the areas of application of the sensor systems, gives instructions about the utilisation potential and the restrictions of the systems and is planned as an aid for selection.

Neither the direct quality monitoring of the executed weld nor any of the procedures suitable for this are included in the area of responsibility of the sensors under consideration here (DVS 0954 technical bulletin entitled "Welding data as an aid for quality assurance in the case of automatic gas-shielded metal-arc welding" which is under preparation).

welding processes. In this case, the utilisation of sensor systems generally serves the objective of safeguarding the quality of the welded joint in an efficient and economically viable way.

In this respect, the successful utilisation of the sensor systems depends, in particular, on the analysis of the outline condition as well as on the requirements on the demanded function of the sensor. The influencing variables can be systematically divided into the categories:

- workpiece-related influences

- installation-related influences

- influences relating to measuring and regulation technology

- process-induced influences

Three sensor principles have become widespread in practical application:

- optical sensors

- tactile sensors

- arc sensors

The description of the measuring principles on which these systems are based is included in Part 1 of this technical bulletin. The practical applicability of the individual systems is now to be dealt with below taking account of the influences specified above. Since three sensor principles (the optical sensors, the tactile sensors and the arc sensor) have essentially gained acceptance in practical utilisation, this technical bulletin also primarily refers to their specifications.