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Voltage Testers, Which One Do I Need?

Whether you’re a professional, hobbyist, or weekend warrior, having the proper voltage testers can make a big difference to your safety and the efficiency of your work. Essentially, a voltage tester helps you determine whether current flows into a piece of equipment. If current flows through a piece of equipment or an electrical outlet, the light or indicator of the tester will glow. Conversely, if the indicator doesn’t light up, it means that the equipment or outlet might be broken or flawed.

Let’s learn more about the specific types of voltage testers and which ones you should have in your toolbox.

Types of Voltage Tester

When testing for voltage, you can make use of specific types of voltage testers. For example, if your goal is to check for current, you will most likely need a simple neon tester. It’s the simplest type of voltage tester ideal for small projects. Besides the neon circuit testers, here are other types of voltage testers and other ways you can use them;

Analog Volt-Ohm Meter

It measures voltage or voltage changes. You can get the readings by looking at the needle pointer of the device. Permanent Volt-Ohm meters usually come as separate equipment. However, there are some cases when you can have them integrated in a multimeter device or similar.

Digital Multimeter

Primarily, digital multimeters measure voltage, resistance, and current. It’s a standard tool used in running diagnostic tests on all types of electrical equipment. Compared to its predecessor, digital multimeters provide more accurate readings. A typical modern-day digital multimeter also comes with additional features that can help you get more information about your electrical device.

Continuity Tester

The continuity tester is similar to a multimeter. However, it’s less complicated as it primarily focuses on checking whether a circuit is open or closed. Testing for a circuit’s continuity is crucial in identifying damage in a device’s critical electrical components. Continuity tests may also allow you to determine the quality of the soldering and measure resistance.

Voltage Detector

Similar to neon voltage testers, voltage detectors help you determine if current runs through an electrical device. However, instead of simply producing light signals, a voltage detector also makes sound signals to indicate a flowing current.

Non-contact Voltage Tester

Otherwise known as inductance testers, this type of voltage testing equipment is arguably the safest and easiest option to use. As its name suggests, it doesn’t require you to touch an electronic device or wire with this tester. Instead, the wand automatically senses voltage. It’s a standard option among homeowners and hobbyists.

Solenoid Voltage Tester

Solenoid volt meters detect polarity and voltage. Most electricians use this tester because it works for both AC and DC voltage that reaches a maximum of 600 volts. You can easily find one at electrical supply companies as well as retail shops.

Digital Clamp Meter

Professional electricians also have a digital clamp meter in their toolbox. Essentially, this device works as a multimeter but offers more functionalities. The jaws of the clamp meter open and close around a conductor allowing for a reading to be displayed on the meter.

Insulation Tester

An insulation tester utilises a high voltage DC charge to test and measure resistance in wires and electronic components. Primarily, it detects current leakage or broken insulation. If you have such problems, then your device or electrical system might be at risk of fire, blown fuses, tripped circuit breakers and arc faults.

Loop Tester

Loop testers can help you assess if a fuse or circuit breaker can protect your electrical system should a fault or disruption occur. It also allows you to determine if your existing circuit can disconnect fast enough to reduce risks for overheating or fire.

Find the Right Electrical Testing Tool at Metrotest

Here at Metrotest, we offer a variety of electrical testing tools. Besides voltage testers, we offer all kinds of tools that can help you maintain the safety of your appliance, electronic device, or electrical system.

Here’s a quick list of the products you can find at our shop:

Electrical Testing ToolsPrice Range
Insulation Testers$715 to 3,600 incl GST
Loop Testers$1080 to 3,900 incl GST
Clamps and Digital Multimeters$174.80 to 375 incl GST
High Voltage Insulation TestersGet a quote today!
Power Quality Analysers$2,733.70 to 14,960 incl GST
Multifunction Installation Tester$1,430 to 3,600 incl GST
Cable Location Equipment$2,047 to 18,850 incl GST
RCD Testers$333.50 to 1,430 incl GST


Learn more about our product offers at Metrotest today! You can send us a quick message or call us at 0800 638 768.

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PAT Servicing

Like cars, portable appliance testing (PAT) devices need preventive maintenance and calibration to ensure top performance. A faulty car may still run, but it may not be safe to drive in. Similarly, a faulty tester may still work, but it may pass items that are actually unsafe. It’s a risk you don’t want to take.

When you’re a test and tag service provider, businesses will rely on you to ensure the safety of their electrical machines, so ensuring the accuracy of your readings is your responsibility. There should be no margin for error.

In some testing cases, a small discrepancy in the results could mean the difference between an electrical device passing or failing incorrectly. For example, when you’re performing tests on Class II appliances where you get minute values to begin with.

Our PAT tester is only a few months old, when does it need calibrating?

Most new machines are calibrated in the production plant by the manufacturer. So you won’t need to have it tested or calibrated until it is a year old.

In the test and tag industry, the general consensus is that servicing PAT devices must be done every 12 months regardless of the type of tester you use. It is also stated in the AS/NZS 3760 Standard that regular intervals are necessary to ensure your PAT equipment is working as it should.

However, if you suspect something is wrong with your PAT tester, you should book a repair immediately. Or if you are testing frequently, you might need to have a calibration done sooner.

Do you service PAT testers that were not bought from you?

Yes, we do! We calibrate and repair all major brands of portable appliance testers, such as:

  • Megger
  • Seaward
  • Metrel
  • Sonel
  • Fluke
  • Aegis
  • Ethos
  • MTI

We have a wide knowledge base and a vast experience across different product types including standard testing devices.

What does servicing involve?

Our in-house repair team performs a comprehensive calibration service, including testing, refurbishing, dismantling and firmware upgrades (when necessary). You can opt for a ‘MedCal’ or medical + calibration, where our techs will open up the tester, clean it out and check for signs of trouble such as loose fittings, overheating, internal battery voltage issues, etc. We make sure to cover all major parameters to a high degree of precision, using the latest diagnostic equipment.

If a tester with printer is sent for a service, we may require you to send the printer in for a check as well. Printer repairs done by us include the brands TSC, ProTag, Sato, Intermec and Zebra. Should our repair team find minor issues or broken parts, we will advise you on the best recourse and if any delays are to be expected due to parts needing to be ordered. The good news is our repair facility in Blenheim stocks a wide range of parts for PAT testers, printers and scanners, so it’s not likely that your device will be out of service for long.

How long does it take?

It will take around five days to have a tester calibrated. But since we have our own in-house technicians and comprehensive facilities, the turnaround time for repairs is just a few days. It might seem too long for a tester to be out of service, but it’s certainly worth taking the time to ensure results are correct.

Meanwhile, to reduce your down time, you may hire one from our range of modern PAT devices while the old one is being fixed. We’ll definitely one to lend that is identical or similar to your own tester. This will help you to keep business going as usual.

Quality Control

All testers that arrive at our calibration house are handled and repaired in accordance with our stringent repair procedures. We use equipment and calibration certificates that are fully traceable to national and international standards.

We store all calibration data digitally, making it easy to locate your results should you lose your calibration certificate. In which case, we can easily email you a copy of your calibration results.

How do I request for servicing?

Download and fill out a Metrotest Service Form to book a repair. Then, either ship your tester or drop it at any of our two repair facilities in New Zealand. Once repairs/calibration is done, we will have it shipped back to you along with your calibration certificate. We’ll also give up reminders for when your tester is next due for its regular servicing.

Contact us on 0800 638 768 for a quote or for more information!

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Test and Tag Equipment

There are different tools used in the testing of electrical equipment and appliances. Here are some of the commonly used ones.

Clamp meters

This is a fairly easy to use test tool for measuring current. It combines a basic digital multimeter with a current sensor. As the name suggests, you clamp the hinged jaw of this tool around a wire, cable or other conductor at any random point in an electrical system. It will then measure the current in the circuit without disconnecting it.

This tool is preferred for measuring high levels of current, with a minimum current range of 0 A to 100 A. Other clamp meters go up to a range of 600 A or 1400 A. It’s a good tool for electrical safety and maintenance, but there are more reliable tools when it comes to compliance.


Also known as a volt-ohm-meter, a multimeter is a handheld device used to measure current (amperage), electrical voltage, resistance and other values. It comes in analog and digital versions. Electricians use it for simple tests as well as for detecting faults and complex diagnostics.

Portable appliance testers

Portable appliance testers (PATs) are handheld or compact devices that test a range of electrical equipment and appliances for different values, i.e. earth continuity, current leakage, insulation, etc.

PATs record details about each test which can be printed on a special tag that contains a PASS/FAIL remark or the actual test values.

At Metrotest, we use PATs for their reliability and accuracy. The devices we use are compliant with the AS/NZS 3760 Standard (In-service safety inspection and testing of electrical equipment). Below are some of the test tools we trust and recommend:

  • Metro iPAT SupaPAT – A comprehensive testing package that includes a user-friendly Sonel Metro iPAT Standard Set, thermal transfer printer, scanner and software – all in a specially designed carrier bag.
  • Metro iPAT – A safety and compliance tester with user-friendly operating software (OS) with easy data management. Features Dual Time Tags (DTT) which makes retesting easier. Other features include: manual & automatic test codes; single test ability; high-current earth bond test; RCD tests both installation and portable RCDs (includes ramp test).
  • Sonel Metro EasiPAT – A compact and reliable portable appliance tester for do-it-yourself testing. It comes in handy when testing residual current, leakage, insulation, polarity and earth bond (200mA, 10A). It features a 1-push test selection, light-up LCD display, direct Wi-Fi capability and a Pass/Fail indicator.
  • Megger 150R – A cost-effective portable appliance tester that packs in functionality. The PAT150R is ideal for a wide variety of testing applications such as dual insulation testing (250/500V), portable equipment testing, portable RCD lead testing (10mA/30mA), and mains powered leakage testing (230V). It has adjustable PASS testing limits and onboard rechargeable batteries.
  • Metro 6201A – An entry-level portable appliance tester for low-volume applications. This basic PAT is a good choice where handwritten tags and manually recorded information is all that’s required. It can perform single phase appliance testing up to 10A; earth testing (200mA); insulation testing (250/500V); mains powered leakage testing (operational – 230V); and lead testing.

Clamp meters and multimeters can be connected to your smartphone to make your readings easier. On the other hand, PATs have an onboard memory which can save anywhere from 1,000 to 1,000,000 items. That being said, memory size is not a critical factor in choosing your own PAT as data must be transferred regularly to prevent loss or theft. Most PATs today can save between 10,000 to 50,000 items.

Label printer

Once a test is completed, the appliance tested will have to be tagged. This tag is made of a special, durable material that’s resistant to tearing or fading. This is to ensure that the tag is intact and readable at all times. testing, the person testing will print tags directly from the PAT memory using a suitable printer. The tags must be made of a tough material that is resistant to tearing, damage or fading.

For testers that do not have an internal memory, there are apps available for direct communication from your smartphone to your tester for saving results.

For more information about testing and tagging equipment, ask the experts on 0800 638 768 (NZ) or 1800 789 973 (AU).

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PAT Tester Comparisons

Are you interested to know which PAT tester is the one you need? When selecting a PAT tester, it can be difficult to know which has which features, which features you actually need, and how they compare price wise.

We have made this video to explain all that. Mark Goldthorpe, Director of Metrotest, explains several popular PAT testers including testers by Seaward, Megger and Sonel, their features, price, and how they compare:

If you are looking at purchasing a PAT tester, we highly recommend you watch this video. If you still need assistance in selecting a tester, you can contact us on 0800 638 768 and we will help you select a PAT tester that best suits your needs. You can view our online range of PAT testers here.

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Electrical Test Equipment Calibration: Why Is It Important?

Electrical calibration, in a nutshell, is a process of verifying an instrument’s accuracy. By default, every instrument that leaves the manufacturing plant is calibrated and certified based on recognised standards.

So why the need to calibrate, you might ask?

As with most devices, the components in your electrical testing instrument may shift over time. The shift may be small and insignificant, but in some cases it may cause a slight difference in measurement. The components are more likely to shift or get damaged if your instrument was accidentally dropped or hit against a hard surface. Your instrument might still work after such events, but you can’t be sure that it will still give you precise results. Calibrating your device gives you quantifiable confidence in its measurement accuracy and performance.

Calibration is especially important in cases where you are working with tight tolerances wherein proper operation of safety systems and processes requires accurate measurement. For instance, when testing Class II appliances where you’re working with small values, a minute discrepancy in the results could pass an item that should be failing, and vice versa. Or when you are trending data, and the meters you use for the same test produce different results. As far as electrical safety goes, using a less accurate electrical test instrument presents a number of risks and legal repercussions.

Electrical calibration

Technically speaking, electrical calibration is a process of verifying and/or adjusting the performance of any instrument used to test or measure electrical parameters (i.e. voltage, current, resistance, etc.).

Some people mistakenly call two meters “calibrated” if they both give the same reading during a field comparison check. But this does not necessarily prove that the two meters are accurate – they could both be “out of cal” condition by the same amount. A simple field check does not reveal the real condition of your electrical testing device. There must be a known standard to which the instrument is tested.

You can send your electrical test equipment to an accredited metrology lab or calibration specialist like Metrotest, who will check your testing equipment’s performance and key properties using precision devices that are at least 10 times more accurate than the unit under test (UUT).

Sending your device for calibration essentially means that you are authorizing the calibration house to carry out repairs or correction to bring the device back to “in cal” condition.

You’ll receive a report showing how your instrument compares to recognized standards, what errors were found and what corrections were done.

Calibration procedures

Calibrating your test instrument is a given, so the real question here is how often you should calibrate your tools. This will depend on the brand you’re using and how well the device is handled.


For new devices with calibration certificate, Sonel recommends the next metrological inspection within 13 months from the purchase date, and not later than 19 months from the manufacturing date. Pursuant to standard EN ISO 10012-2003, a 13-months interval for testing must be observed.

Sonel calibration includes voltage, current and resistance calibration for instruments used for electrical and non-electrical measurements, including:

  • Electrical safety meters
  • Multimeters
  • Meters for electrical protective measurements: earthing resistances, insulation resistance, impedance and resistance of short-circuit loops, RCD parameters, etc.
  • Meters for measuring low resistance values
  • Power quality anlysers


With the exception of digital mutimeters, current clamps and voltage testers, every Metrel device gets an ISO certificate when it leaves the production floor. Metrel’s default calibration includes installation testers (e.g. Eurotest, Instaltest, Insulation test), test equipme

nt (e.g. Clampmeters, Resistors, Multimeters), safety appliance testers (e.g. PAT, CE Multitester), and test equipment for environmental conditions (e.g FonS, Multinorm).

Calibration services will include adjustment, that is, bringing the instrument into a state of performance that is suitable for its use. All procedures are written a guarantee of reliability and repeatability of measurements. Metrel does not accept calibration request from end users, so you’ll need to send your device to an accredited metrology lab.



Megger tester calibration includes resistance function verification and voltage function verification. The procedure measures a resistance by generating a voltage. The value of resistance is computed using Ohms Law: V=IR. Megger has its own calibration box which is used to provide an analog resistance for the unit under test (UUT). The resistance output and voltage display of the calibration box is compared to that of the UUT’s.

Calibration can also be done using a Fluke multimeter as a reference standard. This gives measurement data on the entire range of your Megger.


Seaward has a Tool Tester Checkbox that is designed to make calibration safe, simple and quick. It allows regular calibration to be a part of your safety programme. Seaward PAT testers are recommended for calibration on an annual basis. But for low-usage instruments, calibration interval may be extended under certain conditions, i.e. if the test equipment are regularly checked using the Checkbox and there is no deviation in performance.


All electrical testers are required to have annual calibration. While you can use a calibration checkbox to ensure the continuous accuracy of your CEM device, it does not equal a full in-house calibration which tests tolerances and full instrument ranges in a controlled environment to ensure the manufacturer specifications are met. At Metrotest, we use traceable standards for our calibration services and we issue a detailed certificate outlining all value obtained under calibration.


The Aegis PATROL tester has inbuilt functional test features and a recommended manual procedure that must be performed regularly for self-checking the correct operation of the device. The PATROL performs a Self Check on power up and before each test sequence. In addition to these functional tests, Aegis recommends that your tester must still be sent for calibration every 12 months at minimum. If your device is used under harsh environments or is mishandled, the timeframe must be shortened to ensure it operation at peak performance.


Specifically for the Trio SafeTCheck PAT tester, the routine calibration interval is 12 months. It is recommended that all data is downloaded prior to sending your instrument for calibration, as some data may be lost during the process. The calibration is usually no different from other manufacturers’ testers, and will take anywhere from 2 to 5 days to ensure all results are correct.


Wavecom testers are typically supplied with a calibration certificate valid for 12 months. The manufacturer recommends an annual routine calibration or verification of instruments as prescribed under the AS/NZS 3760:2010 Standard. This must be done only by Wavecome Instruments or by authorised service agents.

During calibration, your PAT tester is checked to ensure operation within certain tolerances. Multiple checks are made are different ‘reference points.’ Depending on the results, your device may or may not need adjustment or repair. The operating firmware may be updated and the calibration settings may be changed.


Re-calibration can be done by Kyoritsu, your distributor or an approved calibration house. At Metrotest, our qualified technicians can calibrate and adjust your Kyoritsu PAT tester to all relevant manufacturer and safety standards. We will issue a detailed calibration certificate traceable to national and international standards. Please check that your instrument does not have any structural abnormality prior to sending it for a metrological test.

Calibration is a form of quality and safety assurance, which allows you to use your electrical test equipment with confidence.

For more information, please contact us on 0800 638 768 (NZ) /1800 789 973 (AU) or drop us a line to

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AlphaPAT Mi2142 Review

The AlphaPAT Mi2142 is by far the best portable appliance tester (PAT) Metrel has ever made. It’s been a top seller in the UK, NZ & Australian markets since 2004.

Although time moves forward and it has much newer competition today, it remains a good choice if you are looking for a tester that does real safety testing, not just compliance testing.

There’s a big difference here. A real safety testing PAT has the ability to really test the protective earth on Class 1 (earthed) equipment at a high current, ideally 10 or 25 amps. On the other hand, a compliance PAT tester tests with a maximum current of 200 milliamps (0.2 amp). Suppliers often won’t tell the uninformed about this, but rather just say it does an earth test. But a test current of 200 milliamps is almost a pointless test!

This low-current-only ability is like testing life jackets by attaching a 20 kg weight – it might be good for a child’s size but not much point if the wearer weighs 90 kg!

More about the AlphaPAT Mi2142

Firstly, it’s a reliable and cost-effective tester which offers downloadable memory and packs an extensive list of additional testing features including touch leakage current, substitute leakage current and low range PE leakage test.

It is powerful yet lightweight. It can store up to 1000 items (test data and results) in its inbuilt memory, which can be downloaded into the default Metrel PATLink software. It also allows you to scan barcode tags (appliance ID field only. There’s also an option for creating PAT reports, writing invoices and exporting data in different formats when you upgrade to SimplyPats 7 Software (purchased separately).

A Brief History

AlphaPAT got its name from Alphatek, the Metrel distributor in the UK at the time. Around the same time it was introduced in 2004, it was changed at the request of Metrotest NZ and an ingenious 3-digit auditable code was introduced. The code started with either a 1 or a 2 depending on the safety class of the equipment to be tested, i.e. Class 1 earthed or Class 2 double insulated.

This coding system is so simple yet so effective when building an auditable system that it is still used today by Metrel and Sonel – the common denominator here being the trademarked SupaPAT, which is available from Metrotest.

Apart from the coding, other things like the ability to perform powered up 3-Phase testing and an automated label printing were also introduced. When used with the printer, the AlphaPAT became a very quick and auditable real safety PAT testing system.

It was eventually to be superseded by the DeltaPAT, which in our opinion isn’t a patch on the AlphaPAT. The Delta has proven popular but most people using the Delta PAT are unaware it is really a compliance only PAT, and those selling it likely just don’t care!


In many respects, when it was released onto the NZ and AU market, the AlphaPAT was ahead of its time. Even today, there are only a few devices like the AlphaPAT that offers 3-phase appliance testing compatibility – not even big brands like Megger!

The AlphaPAT can perform various auto tests suited for electrical appliances of different types and construction classes. It is well built and mostly easy to work on, unlike another brand starting with an S, which shall remain anonymous. We like the fact that there’s no need to squeeze it in a vice to get it back together.

Calibrations and adjustments are generally easy. Some AlphaPATs tend to drift but usually not between calibrations.


Admittedly, the AlphaPAT is not perfect. For one, its alphanumeric keypad makes data entry a bit of a drag. This is arguably the biggest reliability issue which is fortunately very simple to fix – you just replace all 23 switches with a better quality switch and problem is solved! Interestingly, the manufacturer never acknowledged the problem even when it became very obvious. Apart from the switches, it has only the normal common part failures like relays, transformers and other electronic components.

To resolve this inherent issue, Metrotest developed an after-market modification whereby another PCB was installed internally to support a QWERTY keyboard.

The fact that the AlphaPAT cannot do the required RCD testing in NZ and AU is another downside. Moreover, the tester downloads via a RS 232 port, which many modern computers don’t have anymore.

Despite all these limitations, there are still multiple users out there with a hundred plus AlphaPATs – we know of one company that has close to 400 of these testers still in use! So we suspect that they’ll still be around for a while!

Final Thoughts 

Summing up, the AlphaPAT is probably Metrel’s best PAT. It joins the list of the best PATs ever built – by any manufacturer!

Metrotest haven’t had more than a handful written off as “can’t be fixed” and, considering their age, that’s pretty impressive.

Should you consider another comparable tester, we believe the best real safety testing PAT alternatives would be the EasiPAT 10, the Alpha SupaPAT and the Ipat SupaPAT. The latter two both draw their DNA from the AlphaPAT and are leading the market of real safety testing devices.

Finally, it’s time to give it a score from a scale of 1 to 10, with 10 being the highest:

  • When it was first released in 2004: 8
  • How it compares now to other PATs on the market: 7

Test well and stay safe!

For more information about safety, click here.