Do I Need To Calibrate My PAT Tester?

Getting your Portable Appliance Tester calibrated yearly is an important process for anyone who regularly undertakes testing and tagging.

Just as your car requires a service periodically, your PAT tester requires maintenance to ensure it is working as it should. If a PAT tester isn't calibrated properly, results will often become skewed and the tester will pass items that should be failing and vice-versa.

For example, when performing tests on Class II appliances - as the values are so small to begin with, a small discrepancy in the results could mean the difference between an item passing or failing incorrectly. There's a huge number of reasons as to why this occurs, from general wear and tear, internal and external damage or simply a component defect. Regardless, there's no way of knowing if the values are correct without it being checked periodically.

Calibration is essential to ensure that your Portable Appliance Tester provides accurate results, which in turn reduces the risk of errors in the testing and tagging process. However, the benefits of calibration go beyond just accuracy. Here are some of the advantages of regular calibration:

  • Improved Reliability: Calibrated PAT testers offer consistent and reliable performance over time. This reliability will give you more confidence when you’re out testing and tagging, therefore minimising the need for retests and reducing downtime in operations.
  • Cost Savings: As previously mentioned, regular calibration helps detect and rectify minor issues early, preventing them from snowballing into costly repairs or equipment failures. Additionally, accurate testing results help identify faulty appliances promptly, allowing for a faster, more efficient, & safer testing and tagging process.
  • Compliance: The AS/NZS 3760 specifically mentions the importance of getting your Portable Appliance Tester calibrated. By complying with these requirements, you can maintain your business's reputation and meet legal and regulatory obligations.

How often does a PAT Tester need to be Calibrated?

The AS/NZS 3760 standard states that regular intervals are required to ensure your PAT tester is working accurately. Various factors influence the frequency of calibration such as usage intensity, environmental conditions, and what the manufacturers recommend. In saying this, the general consensus is that Test & Tag Machines will basically require a calibration every 12 months, regardless of what type of tester you use.

It's also according to our test and tag experts one of our top 3 ways to ensure your Test & Tag Machine stays healthy for the long haul. It usually takes about five business days to have a tester calibrated, so it's certainly worth taking the time to ensure your results are correct.

We calibrate all tester brands here at Appliance Testing Supplies - simply head to our calibration area and you can have it booked in under 2 minutes. Once completed you'll receive a calibration certificate which confirms it has been calibrated in accordance to manufacturer instructions. 


What happens during the Calibration Process? 
Calibration Process

(The estimated time for standard calibration is 3-5 business days, if the tester is sent away to the manufacturer, it may take up to 2 weeks. You may check the turnaround time for your specific brand here.)

Once we receive your appliance tester, we'll start running it through a variety of tests to make sure it's working properly. For instance, we check all of the functions of the tester against known (also calibrated) values and then adjustments are made where necessary to restore the tester to the correct values.
It's also a really good opportunity to get the latest firmware loaded (if applicable) which can offer faster operation. Lastly, the calibration warning message that may be displayed on the PAT tester can now also be removed or reset.
During the entire process, we keep you updated every step of the way and once completed it usually takes 3-7 business days to get your tester back.