PAT Testing Equipment

PAT testing is a method used to ensure electrical equipment and appliances are safe to use, and fit for purpose. This form of electrical inspection relates specifically to the assessment of devices located in any given workplace. Indeed, it is the responsibility of all employers to ensure equipment does not cause a risk to the health and safety of its workforce. There are two items of legislation that endorse this concept, the Health Safety at Work Act of 1974, and the Electricity at Work Regulations compiled in 1989. Both of these articles state that electrical appliances must be appropriately maintained to mitigate against the threat of employee injury.

The importance of PAT testing

As this concept relates to all electrical appliances within working contexts, PAT testing has proliferated in recent times. Nowadays, workplaces are subjected to a continuing growing reliance on electronic equipment, systems, and controls. Therefore, PAT testing has become increasingly vital in contemporary contexts. Indeed, the necessity of PAT testing has become two-fold. Firstly, promoting the welfare of staff has positive impacts on employee engagement, reduces absence, and makes teams feel more secure. These factors are clearly of benefit to businesses and their respective stakeholders. However, additionally, the need to retain the functionality and performance of electrical equipment has become vital. If this is compromised, then company productivity and output can be severely undermined. Therefore, commercial and industrial dependence on electrical equipment has become index-linked to the importance of PAT testing services.

Although there is no legal requirement to PAT test, the vast majority of employers embrace a regular testing schedule. This not only provides assurances on the efficiency of their equipment, but also allows them to demonstrate a level of management control. In doing this, on-site leadership teams can show both internal and external auditors steps have been taken to protect the wellbeing of their teams. Therefore, on receipt of the PAT testing certification given on completion of an assessment, local managers should file this documentation into a compliance cabinet or safe location.

Considerations for frequency of testing

Most employers will look to establish a PAT testing routine that corresponds to the style of their operation, and risk level of their equipment (more on this to follow). However, it should be noted that there is no formal obligation to PAT test, and there are no mandated timescales for its delivery. Therefore, in theory, businesses can test as little or often as they please. Nevertheless, as it’s in their interest to preside over a regular PAT testing programme, employers will generally ensure equipment is tested once per annum. However, again, this is dependent on their processes, and nature of electrical devices. It may be advisable that certain equipment is tested more or less frequently. More on this to follow.

Earnings potential

Given the volume of appliances in the vast majority of workplaces, PAT testing has become an integral part of the electrotechnical industry. Indeed, many electricians perform this format of testing on a regular basis. In theory, due to its lack of statutory status, PAT testing does not need to be executed by a trained professional. However, it would clearly be a risk if an employer allocated this activity to an inexperienced individual.

Due to its integral nature, and the sheer scale of unit quantities, PAT testing has become an increasingly lucrative endeavour for electrical workers. On average, firms charge between £1-2 for each appliance tested. In an industrial setting, relatively experienced testers can preside over the assessment of around 150 items per day. This figure increases to approximately 300 items when applying the same task to an office environment. Therefore, one can easily grasp the level of financial opportunity available.

PAT testing equipment and accessories

In order to deliver compliant, competent, and safe PAT testing procedures, electricians use a range of approved equipment and accessories. This article intends to review the scope, function, and application of these PAT testing tools. Included within this narrative will be an analysis of when particular equipment is deployed, how the classification of an appliance impacts upon the selection of tools used, and how the conditions of a specific location can affect the regularity of testing practices.


There are arguably four main groups of PAT testing equipment. These are as follows:

  1. Basic Pass/Fail testers,
  2. Advanced PAT testers
  3. Computerised PAT testers
  4. Medical safety testers

Although there is clearly an element of crossover between all of these appliances, each offers a different testing service. The use of these contrasting tools is dependent on context, location, and desired measurement data.

Basic Pass/Fail testers

This entry-level piece of testing equipment is readily used by a range of electrotechnical contractors. Indeed, their propensity for being both user-friendly and relatively inexpensive, makes them attractive purchases for numerous industry stakeholders. This tool presents the user with a fairly limited amount of information with regards to testing results. Nevertheless, all of the essential facts required are suitably displayed. Moreover, electricians can swiftly acquire an answer to the most pressing question; whether appliances have ultimately passed or failed their test.

Within this bracket of testers, there are both mains-powered and self-contained battery kits available. The latter is broadly accepted as the favoured device, as this provides some tangible advantages over mains-powered equipment. In larger-format workplaces, where appliances are readily spread out, a battery-powered tool possesses a superior portable capability. Furthermore, most of these devices come equipped with an integrated pass/fail lighting system, which offers a more efficient method for registering the outcome of a test.

Basic Pass/Fail equipment supports the execution of three testing disciplines. These are as follows:

  1. Earth continuity testing
  2. Insulation resistance testing
  3. Polarity testing.

Again, results shown will not be all-encompassing, but the device screen will still present the tests’ key findings. Unfortunately, given the limited storage capacity of these machines, no testing data can be saved.

Advanced PAT testers

As the title suggests, this style of equipment offers provision for a wider scope of testing formats. They can also record and retain detailed levels of information. Although this tool has the ability to produce substantially more data, this isn’t reflected in the price differential between each device. Although more expensive than their more simplistic counterparts, Advanced PAT testers are still relatively affordable, and therefore electricians should weigh up whether opting for a more sophisticated piece of equipment is a more profitable investment. Cost of these items is clearly contingent on the brand, functionality and system complexity. Therefore, individuals should take time to review what their own requirements are before purchasing.

Again, these testers are recognised for their ease of use and simple navigation. In contrast to basic models, Advanced PAT testers have the capability to store considerable amounts of testing statistics, which are swiftly processed from the testing results screen into recorded data. Some of these devices can patch figures over to computers, allowing users to scrutinise generated information.

However, this equipment isn’t quite able to cover each and every format of testing. Furthermore, their inability to recalibrate testing parameters in different conditions can prove frustrating. Nevertheless, Advanced PAT testers can adjust to a broad spectrum of measuring requirements. This includes:

  1. Portable RCD (residual current device) testing
  2. Adjustable PASS limit testing
  3. Substitute and mains powered leakage testing
  4. Fuse Testing
  5. Lead Polarity testing

Testing ‘kits’

In the case of both basic and advanced equipment, testers can be bought in isolation or as part of an all-encompassing ‘kit’. These packages provide accessories, supplementary equipment and supporting collateral intended to make the implementation of safe and compliant testing easy. Therefore, for most electricians, particularly those with limited experience, it’s recommended that testing appliances are bought as part of an enveloped set of supplies as described above.

Computerised and Medical Safety Testers

Medical Safety Testers are specifically designed to address PAT testing in medical environments. These devices have automatic detection features which allow them to determine the classification of electrical equipment (more on this to follow). Furthermore, Medical Safety testers have parallel testing sockets which enable mains-powered appliances to be tested independently of their power supply.

These devices are less commonly used in PAT testing activities, but nevertheless still hold considerable popularity. Computerised PAT test equipment has flash testing capability, allowing appliances to be safely subjected to high voltage testing conditions. This is occasionally referred to as ‘high potential dielectric strength testing.’

PAT testing accessories

In accompaniment to bulky pieces of equipment hardware, most electricians take advantage of a range of supporting PAT testing accessories and materials. These are deployed to make testing procedures more accurate and organised, and increase result accessibility for clients. There is a multitude of different accessories used to support this endeavour. We’ve picked out some key items that one may witness when observing the complete PAT testing process. However, the following list is certainly not an exhaustive list of the types of supplementary materials an electrical professional may use.

PAT testing labels

These simple but highly effective stickers are used to denote which appliances have ‘passed’ and ‘failed’ their PAT testing assessment. The materials used to produce these labels are durable and suitably resistant to general wear and tear. This is because of the desire to keep them in readable condition, as clear ‘pass’ labelling serves to increase assurance in workplace environments.

PAT test adaptors

Adaptor extensions facilitate the testing of unique electrical items, whose characteristics do not conform to standardised testing devices. The most frequently seen adaptor in the industry is the IEC extension adaptor. This is a relatively simplistic contraption that aids in the testing of various pieces of equipment.

PAT register

Quite simply, this is either a handwritten or digitised record of PAT testing information. Capturing data in a book or software programme enables electricians to chart the testing history of specific electrical appliances.

PAT testing printer

This equipment allows electricians to produce other label formats. Aside from basic pass or fail information, installers are often keen to note down some other key details. This could be the date, name of contractor performing the test (perhaps themselves!), or a specific location within a building (such as a particular room or floorplate). A printer enables testers to record additional information onto various label templates.

For more advanced PAT testing professionals, printers are also utilised to produce barcodes for each device. This allows them to assemble a codified record of all activity and creates a slicker process for re-visiting the testing status of an item or booking in future assessments. If a barcode system is exploited, then individuals will also need to purchase an appropriate scanning tool. Additionally, ink will need to be routinely replenished dependent on usage.

PAT testing scanner

As referenced above, scanners can be used to support the establishment of barcoded recording systems. Given their widespread use in a number of industries, scanners are relatively easy to find, and won’t cost an arm and a leg to acquire.


As alluded to earlier, PAT testing approach, and with it the utilisation of its four main categories of tester devices, is dependent on numerous factors. The proposed regularity of testing is also based on the same set of variables.

One of the key influences behind the type and frequency of testing is electrical equipment classification. Each appliance, regardless of sise, usage, or function, comes equipped with a specific safety rating, known as its ‘class’ of orientation. There are a number of gradings in operation, but all are ultimately organised under three key headings; Class I, Class II, and Class III. These are ranked in descending order in correspondence to their level of potential danger to the user. Therefore, Class I items are recognised as the most dangerous, and Class III appliances are interpreted as the least hazardous.

For PAT testing purposes, each classification has a slightly different assessment remit. Class I equipment requires a full PAT testing approach, Class II items only require insulation resistance testing, and Class III appliances technically do not require any testing activity whatsoever. Below, we’ve provided some examples of appliances, and categorised them by their typical classification rating.

Class I

  • Refrigerators
  • Microwaves
  • Kettles
  • Irons
  • Toasters
  • Extension leads

Class II

  • Hairdryers
  • DVD players
  • Televisions
  • Hedge trimmers
  • Lawnmowers

Class III

  • Laptops
  • Mobile phone chargers
  • Torches
  • Low-energy light bulbs

Equipment categories

There are also some more generalised descriptions that are used to categorise appliances. These often dovetail with the aforementioned electrical classifications. These are recognised as official categories within the electrotechnical sector, as they feature on the IET’s Code of Practice for In-service Inspection and Testing of Electrical Equipment.

For reference, the IET, or the Institution of Engineering and Technology are an organisation that supports the interests of electrotechnical stakeholders in their respective native industries. Furthermore, they produce guidance notes and regulatory literature, such as the Code of Practice articulated above. This helps to enable electrical professionals to complete work in a safe and compliant manner.

This Code of Practice article documents the following categorisations of electrical equipment:

  1. Portable
  2. Handheld
  3. Movable
  4. Stationery
  5. Fixed
  6. IT
  7. Extension leads and RCD extension leads
  8. Multi-way adaptors and RCD adaptors

Again, these terms are also utilised to help gauge the type and regularity of PAT testing required. Each style of appliance has built-in characteristics which demand different testing methodologies and accommodations.

This determination is also impacted by the environment in which the appliance is located. Indeed, when planning testing activity, one should account for the inherent risks of surrounding conditions, and the potential volatility of an item if exposed to a certain set of circumstances. These themes should be captured in workplace risk assessments. This tool supports electricians to make calculated decisions on the most appropriate form of tester to use, and when to coordinate repeat testing activity.

Influences on PAT testing approach – conclusions

Therefore, we can see that there is a significant number of considerations to take into account when determining the application and frequency of PAT testing.

A summarised list of these influencing factors is documented below:

  1. Equipment categorisation. For example, is the appliance stationary, portable, movable?
  2. Equipment classification. Is the appliance Class I, Class II, or Class III?
  3. Frequency of use. Is the equipment deployed sparingly or consistently?
  4. The age of the equipment. How long has it been in service?
  5. Transportation frequency. How often is the equipment moved around?
  6. Competency and capability of individuals using the equipment. Are they fully trained and subjected to regular refreshers?
  7. Location of use. For example, is the equipment used indoors, outdoors, or in hazardous environments?
  8. Previous testing record (if available). How has it performed in historical PAT tests?
  9. Manufacturer guidance and advice. Has the equipment producer offered any testing recommendations?
  10. Modification changes or significant repairs. Has the appliance been subject to any improvements, or been recovered from any noteworthy damage?

Application in society

Perhaps the best way to illustrate this variability is to demonstrate this concept in some ‘real-world’ contexts. This should serve to give us a better understanding of how locality, risk level, and appliance characteristics have influenced PAT testing agenda in varying workplace environments.

In the examples below, we’ve referenced some typical work locations and provided their expected templates for PAT testing activity. Remember, as there is no statutory requirement to PAT test, the below commentary acts as guidance, not a set of legal obligations.

Offices, Shops, and Hotels

In these venues, there is an expectation that Class I appliances are tested every 4 years. Movable equipment, inclusive of extension leads and portable appliances, should ideally be tested every 2 years. As for handheld items, guidance dictates that PAT testing should be performed every 12 months.


Construction sites are home to powerful electronic machinery which is used intensively on a daily basis. A robust PAT testing programme is therefore critical to maintaining production levels and keeping equipment in service. Any appliances whose circuits pass over the 110V threshold should be appropriately tested every three months.


Given the nature of educational environments, where young people congregate and move freely around buildings, PAT testing takes on greater responsibility. Indeed, it provides an important layer of protection to potentially vulnerable individuals. Therefore, gaps between test activity should be shortened accordingly. It’s advised that any Class I electronic items are tested each year, with Class II items assessed every twenty-four months.

Public-use equipment

For any appliances used within the public domain, such as equipment found in libraries, council buildings, and museums, the goalposts change again. Stationery and IT equipment need to be ideally checked every twelve months. Any movable, portable and handheld appliances aligned to a Class II classification should also be PAT tested every year. However, similarly categorised items with a Class I rating require a test every six months.


Industrial settings, including commercial food preparation units, manufacturing plants, and warehouses, share similar guidelines to public-use environments. However, unlike public-use scenarios, there are no added instructions based on equipment classification. Indeed, any portable or handheld device should really be tested every six months. Stationery, IT, and movable appliance testing need to be undertaken annually.

Preparation prior to testing

In any testing situation, electricians should take ample time to assess the risk, respect the location, select their equipment, and plan their approach accordingly. Furthermore, before commencing any activity, trained testers should survey the area, and look out for any potential hazards. Perhaps even more importantly, these individuals should also complete a thorough visual inspection of the appliance being tested, and indeed their testing equipment, before conducting any physical work.

Checking for appliance defects prior to physical testing can help protect the tester from various safety risks. It may also change how they approach the onward assessment. Issues such as compromise to plug casing integrity, damaged connections, and evidence of overheating may all be identified prior to PAT testing. Rigorously reviewing tester equipment is also crucial, helping electricians to take preventative action on potential future faults, and ensuring the kit is suitably safe to operate.


By offering commentary on the role, function, and nuances of PAT testing equipment within workplace environments, this article serves to outline the scale, importance, and variance of PAT testing practices throughout the electrotechnical industry.

As we know, PAT testing is an essential enterprise for businesses up and down the country. Ultimately, it allows employers to protect employees from the threats of malfunctioning electronic equipment, whilst maintaining robust operational performance.

The various available PAT tester devices, along with accessories used to complement the act of testing, enables electricians to deliver accurate, compliant and safe electrical examinations. Electrical professionals should select their testing equipment based on the volume of information they wish to accumulate, client preference, and the characteristics of the appliances being tested.

The classification and categorisation of electrical items help testers to make informed decisions around the type and frequency of testing. This is also based on a raft of other dynamics, such as an appliance’s location, years in service, historical testing record, and manufacturers guidance. This endeavour can be supported through on-site leadership teams taking ownership of risk assessments, and ensuring regular communication with hired electricians is maintained throughout PAT testing visits and beyond.

PAT testing equipment needs to be properly maintained, selected wisely, and used to deliver appropriate testing activity to specific appliances and devices. If all of this is achieved, then these pieces of kit can provide assurance, safeguard productivity, and, most importantly, protect individuals from harm or injury.

If you require any further information on this subject, then please consult a tutor, industry stakeholder, or, if possible, a registered PAT tester. If none of these options are viable, then a simple google search will provide some support.

And finally

To allow you to gain a visual understanding of what PAT testing equipment and appliances look like in the flesh, we’ve posted some supporting images below.