Are Your Welding Machines Accurate? A Guide to Validation and Calibration

If you’ve ever dialed in your settings perfectly, followed your WPS to the letter, and still ended up with inconsistent welds…it might not be your welder. It might not even be your process.

It might be your machine.

One of the most overlooked factors is whether your machines are actually performing the way you think they are. Voltage set to 20 doesn’t always mean you’re getting 20 volts at the arc. Wire feed speed can drift. Amperage can fluctuate. And over time, even the best machines fall out of alignment.

That’s where validation and calibration come in. Today we're gonna break down the difference between the two terms, go over common compliance requirements for our industry, and help you get your machines in perfect working order.

Validation vs. Calibration: What’s the Difference?

Although these terms are very commonly used interchangeably, they actually serve two different purposes. Validation is the process of testing your machine’s output to confirm it matches the parameters you’ve set. Calibration, on the other hand, is the process of adjusting the machine so that its output matches those intended settings.

When thinking about validation, you might ask: Is my voltage accurate? Is my amperage where it should be? Is my wire feed speed consistent?

When thinking about calibration, you might ask: How far off are my actual readings from my set parameters? What adjustments are needed to bring the machine back into spec? After adjustment, does the machine now match the intended output? ​
​
To put it simply,  validation tells you if there’s a problem and calibration fixes it! Both are essential to maintaining consistency and ensuring your welds meet required specifications.

Why validation & calibration matter

Every welder knows that even small inaccuracies in your welding parameters can lead to inconsistent weld quality, failed inspections, rework and wasted material, and increased production costs. It's important to get your machine validated so when dialing in, you know the parameters you've set are what your machine is actually putting out. 

Real Talk: Compliance Isn’t Optional

For shops doing code work or following formal quality standards, the stakes are even higher. If your machine output doesn’t match your WPS, you could be out of compliance... even if your settings look correct on the machine! Depending on the code you’re working under, setting up an appointment for calibration may not be optional. So let's discuss a few common compliance requirements you might run into...

AWS D1.5

This common bridge welding code explicitly requires calibration every 3 months.  Routine calibration is required.

OTHER AWS CODES

While other AWS codes may not clearly define a strict calibration schedule like D1.5, they still require that welders are operating within the parameters defined by their WPS.
​
This puts the responsibility on the fabricator to check that machines are performing accurately.

This makes regular validation and calibration a best practice for any code work!

Vertical Divider

ISO STANDARDS

ISO is a quality control standard that companies can choose to adopt. Although the two standards referenced below are not the only ISO standards, they are the ones we see most commonly in this industry.

ISO 9001

Through this specific ISO standard, companies are required to calibrate equipment on a schedule and track that calibration status by maintaining records.

Signs That Your machines are out of calibration

Not sure if your machines need attention from the professionals? The tricky part is that calibration issues aren't always obvious... until they start affecting your weld quality, productivity or inspection results! So let's go over some common warning signs to keep an eye out for.

• Inconsistent arc
  If your arc feels “cold” one minute and “too hot” the next without changing settings, your machine's probably not delivering steady output.​

• ​​Excessive spatter or porosity
  These are often blamed on gas or wire, but they can also be a sign of a mismatch between your displayed and your actual voltage.
• Weld inconsistencies between operators
  If one welder is producing solid results and another is struggling using the same settings, the issue may not be skill related, it could be the machine output varying from what’s displayed.
• Difficulty dialing in
  When it feels like you’re constantly tweaking settings to hit the right result, even with a proven WPS, that’s often a sign the machine isn’t delivering accurate output.

• Failed inspections despite correct settings
  One of the biggest red flags: everything matches the WPS on paper, but welds are still failing inspection or NDT. This often points to a gap between indicated values and actual output.
• Frequent overheating / hitting duty cycle limits
  If your machine is hitting its duty cycle limit faster than usual, it might be drawing more current than the display suggests it is. This will put pressure on your machine's internal components which can be both dangerous and costly.
• Recent repairs, movement, or relocation
  If a machine has been recently serviced, transported, or even just moved around the shop, its calibration can shift.
• Machines that haven’t been checked in 6–12+ months
  Even well-maintained equipment drifts over time. If it’s been a while since your last validation, there’s a good chance your machines aren’t exactly where you think they are.
  

---

Schedule A Machine Validation or Calibration test

​If you’re noticing any of these signs, it’s worth scheduling a simple validation check. This can quickly confirm whether your machines are on target, or highlight where calibration adjustments are needed before small problems turn into big issues. 

Set your team up for success by providing them with the most accurate tools for the job!

Want to make sure your machines are dialed in? Fill out the form below to reach out to the team. We'll get you scheduled for a machine validation and calibration service appointment as soon as possible!