Choosing a PAT Tester

Choosing a PAT tester can be confusing, not because the tests are complicated, but because the type of equipment you’re testing, the records you need to produce, and how well you can interpret readings all affect what’s “best”. This guide explains the main tester types and the features that matter in real-world PAT testing.

If you’re new to PAT testing, start with our how to PAT test guide, which shows the inspection and test process on common appliances. It will also help you understand which tester features actually matter.

PASS/FAIL Testers (PAT Checkers)

Pass/fail testers only display a simple go/no-go result, they do not show the measured values. In practice, you often need the actual reading to make the correct decision, especially for earth continuity, where the limit is 0.1 Ω plus the resistance of the supply cable.

Because cable length and conductor size vary, a fixed pass/fail threshold is always a compromise. The IET Code of Practice notes that if a cable-connected appliance fails an earth continuity test on a go/no-go tester, it may be necessary to measure the actual resistance using another instrument. For this reason, we do not supply or recommend pass/fail testers.

For more detail, see our pass/fail tester guide, and for limits see our earth continuity limit guide and calculator.

Manual PAT Testers

Manual PAT testers are a popular option for lower volumes of testing. Appliance details and results are usually recorded manually, and the tester runs fixed test routines for Class I, Class II and extension leads.

Because settings and limits are often fixed, you may still need to interpret readings, for example allowing for supply lead resistance on earth continuity (see the earth limit calculator), or selecting the appropriate approach when leakage limits and appliance types vary. For anyone learning PAT testing, this is also why recording the measured values (not just pass/fail) matters, it’s one of our top PAT testing mistakes.

The manual PAT testers we recommend are the Kewtech EZYPAT and the Kewtech EZYPAT Plus.

Downloadable PAT Testers

Downloadable testers include a wider range of tests and features, and store appliance details with results for download. This typically makes testing faster and gives better traceability, because you can demonstrate that the tests were carried out correctly and keep consistent records over time.

The Most Suitable Tester

The biggest factors when choosing a tester are how many items you test and what records you need. As a rough guide, for up to around 500 items an entry-level/manual tester can be cost effective. Above that, the time saved by a downloadable tester often outweighs the higher initial cost.

Attending a PAT Testing Course

We strongly recommend attending a PAT testing course before buying test equipment. On the course you can use different tester types, learn which features are genuinely useful, and most importantly, learn how to select the correct tests and interpret the readings in line with the IET Code of Practice. That practical experience makes it much easier to choose the right tester with confidence.

Comparison Table

The table below compares a selection of popular, widely-used PAT testers.

	Seaward Primetest 100	Kewtech Ezypat	Seaward Primetest 250	Kewtech Ezypat Plus	Kewtech Smartpat	Seaward Apollo 400

Battery Powered	✓	✓	✓	✓	✓	✓
Earth Resistance - Low Current	✓	✓	✓	✓	✓	✓
Lead Polarity Test	✓	✓	✓	✓	✓	✓
Insulation Resistance - 500V	✓	✓	✓	✓	✓	✓
Insulation Resistance - 250V	✘	✓	✓	✓	✓	✓
230V Leakage Test	✘	✘	✓	✓	✓	✓
110V Leakage Test	✘	✘	✘	✓	✓	✘
Substitute Earth Leakage Test	✓	✓	✓	✓	✓	✓
230v Load Test	✘	✘	✘	✓	✓	✓
110V Load Test	✘	✘	✘	✓	✓	✘
No trip Portable RCD Test	✘	✘	✘	✘	✓	✓
Test Lead Nulling	✘	✓	✘	✓	✓	✓
Rechargeable	✘	✘	✘	✘	✘	✓
Download Test Data	✘	✘	✘	✘	✓	✓
Programmable Test Limits	✘	✘	✘	✘	✓	✓
Qwerty Keyboard	✘	✘	✘	✘	✘	✓
Label Printer Compatibility	✘	✘	✘	✘	✓	✓
Bluetooth / WiFi	✘	✘	✘	✘	✓	✓
Mobile App Compatible	✓	✓	✘	✓	✓	✓
Calibration Certificate Included	✘	✓	✘	✓	✓	✓

Features

Earth continuity (low current / high current) – There are two approaches to measuring earth continuity: low current and high current. High current testing is designed to stress the earth path and can help reveal weak connections. Low current testing measures the protective conductor resistance at a much lower test current and is generally the appropriate option for IT and sensitive electronic equipment. The IET Code of Practice allows either method, depending on the equipment being tested.

Earth continuity limits – For most Class I equipment the limit is 0.1 Ω plus the resistance of the supply cable. That cable resistance varies with length and conductor size, which is one reason why “pass/fail only” testers can be problematic. See our earth continuity limit guide and calculator.

Insulation resistance (500 V / 250 V) – Insulation resistance is typically tested at 500 V DC. A 250 V DC insulation test is often used for surge-protected equipment that would otherwise fail at 500 V, and can also be appropriate for some older electronic equipment. Modern IT equipment is generally designed to withstand a 500 V DC insulation test.

Earth leakage / touch current – This test powers the appliance and measures leakage current flowing in the protective conductor (Class I), or the current that could flow through a person touching accessible conductive parts (touch current, often associated with Class II and some electronic equipment). It’s a useful real-world test, but it does require mains power and will operate the appliance during the test.

Substitute leakage (sub-leakage) – Substitute leakage tests are carried out at a reduced voltage and do not power the appliance. They are useful where powering the appliance is undesirable, although they are generally less representative than a full leakage/touch-current test.

Load test – Often performed alongside leakage testing, this measures current and/or power consumption while the appliance is running. Most testers only provide a full load test at 230 V.

110 V operation – Some testers can perform leakage and load tests at 110 V as well as 230 V. If a tester can’t operate at 110 V, a substitute leakage test is typically used instead. (It’s also important not to accidentally apply 230 V to 110 V equipment during powered tests.)

RCD trip time – The IET Code of Practice recommends measuring trip times for equipment fitted with an RCD. Some testers require additional measures (for example, an isolation transformer) to avoid tripping upstream RCD protection during portable RCD testing, whereas other testers can perform “no-trip” testing.

Test lead nulling – Earth continuity values are small, so the resistance of the test leads can noticeably affect the reading. Nulling allows the tester to subtract the lead resistance to improve accuracy and consistency.

Battery operation – Battery power makes testing more convenient, but battery-only testers are often limited (typically no high-current earth bond, and powered leakage/load testing may require mains connection). Some battery testers can be plugged into a 230 V supply to enable powered leakage and load tests.

Test sequences / auto tests – Built-in test sequences speed up testing by automatically selecting the correct series of tests and pass limits based on equipment class and type. Even with auto tests, it’s still good practice to record measured values, not just pass/fail, as this helps prove the test was carried out correctly and highlights deterioration over time. (This is covered in our top PAT testing mistakes.)

Label printers – Some testers can print labels directly using stored test data. In many cases this is slower than applying pre-printed labels, and printer/label costs can be significant. If you want a deeper dive, see our PAT label printers article.

Keyboard / data entry – A QWERTY keyboard can make appliance data entry much faster and less error-prone, especially on higher-volume jobs.

Conclusion

The “best” PAT tester depends on the type of equipment you’re testing, the records you need to produce, and how confident you are interpreting readings. If you’re testing higher volumes or need full traceable records, a downloadable tester is usually the most efficient option.

If you’re unsure, the quickest way to make the right choice is to attend one of our PAT testing courses. You’ll learn how to select the correct tests, interpret results properly, and you’ll be able to compare different tester types before spending money on equipment.