Determination of the accuracy of the measurement intruments.
The accuracy of the measurement instruments is checked to +/- 2.5% of maximum values. Tolerance requirements are in accordance with EN60974-1 - EN17662 and EN3834-2
Note: Validation of the complete welding equipment also includes at the same time calibration of attached or built in instruments.
In general, calibration of welding equipment instruments (e.g. ammeters, voltmeters) is only required when the quality/repeatability of the weld depends on accurate and repeatable setting of parameters such as current, voltage, speed, gas flow, pulse characteristics, etc. In the schematic below, you can see when to validate/calibrate.
Metal fabricators who are following ISO 9000:2000 will experience that various norms are becoming relevant. Each norm has reference to other norms and end up with IEC 60974-14 and the validation certificate.
IEC 60974-14 describes a strict method to perform the validation, which is suitable for most applications.
Also SAFETY TEST and maintenance SERVICE CHECK are necessary when servicing welding equipment.