preproom.orgThe online science prep room
You are here: Info Library > PAT Testing > Equipment
Info Library

PAT Testing > Equipment

The days of PAT testing with an analogue multimeter have thankfully long gone. On the market today are many types of PAT tester at a range of prices from around £200 up to top end devices of £1200 plus. There are many available through internet based companies and usual suppliers such as Rapid, and RS Electronics, Many of which you will find in our PAT links page.

Lower end testers

The most simple type of testers are what as known as PASS/FAIL testers. With these you simply connect the appliance to be tested and press go whereupon the tester gives a simple PASS or FAIL result. These simple testers do not usually carry out any other tests apart from the standard 'Earth bond' and 'Insulation' test.

The Earth bond test level is usually set on these machines to 25A which is unsuitable for testing IT equipment. PCs need to be tested at 20-200mA. This therefore limits the type of appliance you may need to test.

Because of the set earth bond test, appliances with longer leads may wrongly fail and as there is usually no way of changing this set limit, retesting is the only option in this situation.

In general, these simple testers are simple to use but they are very limited n application.

Manual testers

These testers are usually a bit more sophisticated than the lower end range. They usually feature an analogue needle type display which moves when you test an appliance. Because this level needs to be read off and recorded by the operator it is more prone to human error. Some have LCD or LED type displays that still need to be read off.

Most manual testers cover 'Insulation' and 'Earth Bond' tests and may also include 'load' and an 'earth leakage' test. Some feature selectable Earth Bond test currents that are suitable for testing of IT equipment.

Digital and Downloadable testers

The top end of the PAT testing market features testers with digital, sometimes complex graphical displays which may take you through step-by-step the testing process.

Some feature memory cards and qwerty keyboards which enable you to manually type in the appliance details and then upload them to a PC.

Top-end testers usually feature all the tests that may be required and some even prompt you to execute a visual check and record its results.

Some have integral IEC sockets for easy testing of mains leads, some provide a 110V for easy testing of 110V leads

Some come with the ability to connect to a barcode reader which when used in conjunction with barcode labels, may speed up your tests greatly.

In general, if you have not got a top end tester, you should try pushing for one. They save you lots of time, they are compact and light. They can store all the testing information so you do not need to write anything manually. They remove the possibility of human error by passing or failing the appliance automatically. They are also coming down in price considerably, meaning that the time they save you will pay for itself in maybe a year or two.