6
CALIBRATION CASE CALIWELD
EN
REMINDER OF THE STANDARD (EXTRACT FROM STANDARD EN 50504)
To comply with standard EN1090, the welding generator settings must be checked. This allows to issue a « Calibration Report ».
The following validation procedure relates to standard EN 50504.
The aim is to ensure a good welding result that can be repeated over time.
The validation of welding equipment in accordance with standard EN 50504 means checking the product performance against its settings.
The validation requires to undertake 5 measurements within the setting range. However, it is possible to validate a smaller range if the customer
requests it.
Select the validation/calibration range of the control or indicator assembled on the power supply as follows:
a) the complete range of the control or measuring device (see note);
b) a partial range of the control or measuring device;
c) the selected points within the range of the control or measuring device.
NOTE
The maximum values of the range for voltmeters and ammeters are given by the no-load voltage and the maximum welding current of the
current source.
Before performing the validation/calibration, it is necessary to agree with the manufacturer, customer or user on options b) or c).
Perform measurements at the minimum setting, maximum setting and at three other points which are at nominally equal distance between
minimum and maximum over full range
The measurement is performed twice (measurement «a» rising and measurement «b» decreasing) after a 10 seconds stabilisation period of the
measured values. Beforehand, it is recommended to leave the product running for 5 minutes before performing the validation process.
The validation must be carried out at least every year and after each repair or modication that may affect the settings.
Only a qualied person can perform these measurements. This person ensures that the test conditions are optimal and the results accurate. We
highly advise to go through the text of the standard before performing a validation.
For specic processes such as Pulsed MIG and TIG AC, user errors and the use of indapated measuring tools may result in measurement errors.
The manufacturer of the welding machine must be consulted.
Welding machine precision
The precision of the settings and/or displays is determined by a category, itself determined according to the welding specications (PQR/WPS) and
the welding machine specications.
Validation type: the type of validation can be «consistency» type or «precision» type.
- Consistency type: Validation on a device with potentiometer adjustment.
- Precision type: Validation on a device with adjustment by digital display.
This category is split in 2 types: «Standard» or «Precision». It determines the tolerance for the welding settings, the measure-
ments taken and displayed on the machine as well as the measuring tools that should be used.
Category Standard Accuracy
Welding machine settings
Current (A)
± 2,5% of the maximal setting between 0
and 25% of the maximal setting.
± 10% of the actual value between 25
and 100% of the maximal setting.
± 1% of the maximal setting between 0
and 40% of the maximal setting.
± 2.5% of the actual value between 40
and 100% of the maximal setting.
Voltage (V)
± 2% of the maximal setting between 0
and 40% of the maximal setting.
± 5% of the actual value between 40 and
100% of the maximal setting.
Wire speed (m/min) ± 10% of the actual value ± 2,5% of the actual value
Welding machine displays
Analog measurement display Class 2.5 Class 1
Digital measurement display 2.5% 1%
Measuring tools
Measuring tools must be at least 2 times more accurate than the required accuracy of the category.
Maximum validity period 1 year 6 months