What is a PAT Tester? 

A portable appliance tester, otherwise known as a PAT tester for short, is an electrical safety measuring device used specifically in the testing and tagging industry to identify whether an electrical portable appliance is safe or not to use.

PAT Testers play a critical role in the test and tag process, as it helps to identify electrical hazards before they can cause harm. By lowering the risk of an accident occuring, it effectively helps protect staff.

In the sections below, we've gone through the main things you need to know about a PAT Tester, who can use it and other important details about the test and tag industry in New Zealand.

Portable Appliance Tester

What does a PAT tester do?

Portable electrical appliances come with certain safety parameters pre-installed by the manufacturer. These parameters then must be checked periodically to determine whether they still meet the New Zealand workplace safety standards - and that's where a PAT Tester comes in.

Here's how it works:

  • You visually inspect the appliance first (more on that below)
  • You connect the appliance to the PAT Tester
  • You select a test on screen and run it
  • The appliance tester gives back a clear PASS or FAIL result

The visual inspection is very important - many faults (like a cracked plug or frayed cord) can be spotted without even turning the appliance on.

Common Tests a PAT Can Performs

The following are some of the more common tests that a PAT tester can perform:

Earth Continuity Resistance: This test is conducted to determine the earthing of an appliance. The PAT tester would determine whether there is a satisfactory connection between the earth pin in a plug and the case of the appliance. This is measured in order to reduce the chances of electrical shock.

Insulation Resistance: This test checks for any breaks or exposed wires or if the plastic coating surrounding the wire has worn off.

Lead Polarity: This test checks for any breaks or exposed wires or if the plastic coating surrounding the wire has worn off.

Leakage Current: This powers up the appliance to check if any electrical current is leaking while it's running. A PAT Tester must be able to perform this test as a minimum in NZ. This will determine if the appliance tester is compliant or not.

What items need to be tested and tagged?

Not every appliance requires testing, but most workplace items powered by mains electricity do.

Generally, an appliance needs testing if it:

  • Is powered by mains electricity i.e. not low voltage below 50V
  • Has a flexible power cord
  • Has a removable plug

Appliances are classified as Class I (earthed) or Class II (double insulated), which determines which tests apply.

New equipment doesn’t need full testing before first use, but it must be visually checked.

PAT Testers

Who can use a PAT tester?

In New Zealand, testing and tagging can be performed by anyone deemed a Competent Person under AS/NZS 3760:2022.

You don’t need to be an electrician, you just need the right training. Completing a recognised Test and Tag Course teaches you how to use a PAT tester correctly and stay compliant.

If you’re unsure how to test or which PAT tester suits your needs, our NZ courses and support team can guide you.

Different kinds of PAT testers

There’s a wide range of PAT testers available in New Zealand, from simple manual models to advanced systems with Bluetooth, printers, and data storage.

  • For in-house testing: Mid-range testers like the Metrel DeltaPAT 3309 BT are great, simple, portable, and reliable.
  • For professional service providers: Consider advanced setups like the Delta Pro Print Pack or Seaward Elite+ Kit, which include wireless printing, data logging, and faster workflows.

Before you buy, ask yourself:

  • How often will I be testing?
  • Do I need to print tags or store results?
  • Will I test a wide range of appliances?

As a rule, the more advanced the tester, the more time and features you’ll gain.

Need help deciding?

Check out our Top 5 PAT Testers of 2025 or browse our detailed Portable Appliance Tester Reviews to compare features. 

For help choosing the right one in plain english, check out our PAT Tester Buying Guide.

Are All PAT Testers Easy to Use?

If you’re new to testing and tagging, one of the most common questions we hear is “Are test and tag machines hard to use?”

The answer depends on the model you choose.

Basic testers are very straightforward. Most have a few clearly labelled buttons (often with icons), and once you’ve completed your training, you’ll know exactly which test to run. These are great if you just want to get the job done quickly and keep things simple.

Mid-range and advanced testers include more automation and features — things like built-in memory, Bluetooth connectivity, custom test settings, and wireless printing. They can take a little longer to learn, but they save a huge amount of time when you’re testing multiple sites or large volumes of equipment.

The good news? We've got you covered. All our PAT testers come with lifetime technical support, setup guidance, and access to training resources. Whether you’re using a basic manual unit or a fully automated kit, we’ll help you get started and feel confident using it from day one.

In Summary

A PAT tester is a must-have if you're working in or around electrical safety. Whether you want to keep your own workplace safe or start a test and tag business, having the right PAT tester and knowing how to use it is key.

If you’re just starting out, we’re here to help. Our friendly team can walk you through choosing a tester, booking training, or answering any questions you’ve got.

Reach out to our team if you're wanting help getting started.