Why is welding machine calibration / validation to required |
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| The quality of a weld depends upon accurate and repeatable setting of parameters such as current, voltage and wire feed speed.
Calibrating your machines ensures that meters attached to arc welding equipment and graduated scales are accurate within allowable tolerances. Each inspection and test includes a certificate for each machine stating whether or not the equipment passed or failed the above standard. If the equipment fails, our engineer will discuss with you what is needed for it to pass. Calibrations and validations are carried out to IEC 60794-14 and our equipment is calibrated to the aforementioned standard. IEC 60974-14 is an international standard that governs the calibration and validation of arc welding equipment. CENELEC, the European Committee for Electrotechnical Standardization, has accepted this Standard. Members are obligated to cooperate with no alterations. It specifies the requirements as well as the procedure for calibration and validation which explains how to take readings and what tolerance we work with. Calibration and (or) validation each have two tolerances, these grades are standard and precision. |
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Our service and what’s included |
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| Calibration and the associated Machine Compliance Test can be carried out on your premises or you can send your equipment to us and will be carried out in accordance with the standard, which calls for a resistive load since a live arc is unstable and inconsistent.
This is carried out at five points across amperage range agreed upon by the welding equipment manufacturer, user or as defined in the welding method. The welding equipment and certificate will be marked with the pertinent information when completed. Welding machines are connected to a calibrated load bank to inspect the actual voltage, amperage, and wire feed speed. The resulting numbers are analysed and obtained for your welding equipment and compares them to the standard requirements to find any inconsistencies. If the necessary procedures aren’t followed, the welding equipment should not be used for manufacturing due to potential quality issues. MIG/MAG, MMA, and TIG systems may all be calibrated. Qualified fabricators must have their welding equipment calibrated at least annually. The standards provide the concepts that will guide the quality assurance process for welded goods. EN 1090 specifies the manufacturing specifications and CE marks for steel and aluminium.
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The Standard
“The Standard“ refers to IEC 60974-14 – the International standard which covers the Calibration and Validation of Arc Welding Equipment and replaces EN 50404:2008. The biggest change from EN 50404:2008 to IEC 60974 is the requirement to take voltage readings under load. This means that load line values are more relevant to the process. The Standard is approved by CENELEC, the European Committee for Electro technical standardization.
The standard lays out the requirements and method for calibration and Validation. It also instructs how readings are taken and what tolerance we work to. The
The standard sets out tolerances for two types of Calibration/Validation. There is the Standard Grade and the Precision Grade.
Calibration / Validation may be carried out over a limited range, as agreed by the manufacturer and user or specified in the welding procedure. The welder and certificate must be marked with the relevant information if this is done.
Calibrations / Validations are to be carried out yearly unless the customer requests more frequent intervals. Cal/Val should be done more frequently if it is believed the performance has deteriorated and after any repairs carried out to the power source or its metering system – i.e. the wire feed unit.
The Standard recommends a resistive load to carry out Cal/Val as a live arc is unstable and inconsistent.
The SMP Calibrator and the certificate produced completely comply with this standard and in turn meets the requirements of ISO 9000 based quality systems including EN 1090
Wire speed Calibration or Validation is now required if meters are present.
The Cal/Val and verification of other equipment involved in welding such as flow gauges, robots, manipulators etc. are covered under a completely different standard – EN ISO 17662
What’s the difference between welding machine calibration & validation?
Under the ne standard a Calibration is carried out on equipment fitted with meters, either digital or analogue and a Validation is carried out on equipment with a graduated scale – usually found on MMA and Tig welders.