AMI Model 217 welding power supply

In welding, the power supply serves the function of regulating current and voltage for different arc welding applications. It is connected to the weld head, where the electric output transfers to the workpiece to melt and fuse pieces together. The consistent electric output is responsible for delivering a weld result free of defects. To ensure this consistency in every welding application, regular inspection of the welding power supply is a must. 

The need for welding power supply calibration may arise from long-term use or due to variations in load or temperature. The different calibration options—independent or manufacturer calibration, can be leveraged to maintain accuracy and precision in the welding process. 

The Need For Welding Power Supply Calibration

The need for calibration comes from the requirement of quality, efficiency, and safety that every welding process needs to abide by. Besides inaccurate results, using a power supply that is not calibrated also poses a serious safety risk. Thus, it is crucial to understand the cause of electric output deviation and the consequences of not addressing the issue.

Below, we have outlined some causes and consequences of the lack of welding power supply calibration.

Cause Consequence
  • Input voltage fluctuation
  • Fluctuation in electrical load & temperature changes
  • Operating life of the power supply unit
  • Electromagnetic interference
  • Inconsistent output leading to weld defects
  • Risk of overheating, electric shocks, and fire
  • Increased downtime and repair costs
  • Noncompliance with industry standards

To summarize, not calibrating a welding power supply severely affects the quality, productivity, and safety of the welding process. Thus, the fabricator must explore the different welding power supply calibration options. 

Calibration Options: Ensure the Accuracy of Power Supplies

Welding power supply calibration can be done in-house, through specialized calibration shops, or sent back to the manufacturer. 

We have detailed each below.

In-house calibration Some calibration processes may be cost-effective if performed in-house. However, there are a few things to note. The process requires:
  • A certified/trained technician
  • Knowledge of calibration equipment and tools
  • An upfront investment for equipment and personnel
Manufacturer calibration This is the ideal option for welding power supply calibration. Given the manufacturer’s knowledge, the cause and requirement of calibration are likely to be identified quickly.
Here are a few things to note about the option of manufacturer calibration:
  • Manufacturers carry out the calibration in a controlled environment, following strict procedures as per the standard.
  • The proper equipment and tools are used for the calibration process.
  • The process may be costly compared to other options with a larger turnaround time.
  • However, most manufacturers provide a warranty to cover the calibration and repairs that may be required.
Independent calibration shops Independent and accredited calibration shops are a good alternative if cost-efficiency is a concern. The advantage of this option is:
  • The shops are accredited, i.e., they have certified technicians and are equipped with all necessary calibration equipment.
  • The process is more cost-efficient than sending it back to the manufacturer.
  • These shops will likely offer faster turnaround times, which means less downtime and more productivity.
  • However, using such services voids the warranty the manufacturer offers, which could cause significant problems down the road.

Periodic Welding Power Supply Calibration For Weld Accuracy

Regardless of the option, welding power supply calibration must be a part of your welding inspection checklist. The frequency of calibration may differ based on factors such as the manufacturer’s recommendation or operating environment. However, a regular inspection will prevent the risks of using an uncalibrated power supply.  
Through regular welding power supply calibration, you can be assured of precision and accuracy in weld results, as well as productivity and cost-efficiency in the long run.  

Arc Machines, Inc. has led the market for decades with its advanced and innovative orbital welding solutions. For inquiries regarding products, contact For service inquiries, contact For developing a custom welding schedule for welding steel tubing, contact us to arrange a meeting.

Engineering Department | Arc Machines, Inc.

The first engineers at Arc Machines were also part of NASA’s Apollo program, and we continue to hold our staff to those that level of drive and quality. Not only do we produce the best welding machines on the market, but we can also build customized machinery—tailored to your operation.

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