Where to start when looking for the BEST Multimeter
If you ask an electrician, a technician, or even a novice electronics enthusiast, what the best multimeter is, they will more than likely rattle off a brand and model that they own, or have used in the past, or have heard about from someone else.
Often the only grounding they have for suggesting their ‘best’ multimeter, is their familiarity with the model or the brand. When it comes to the technical stuff and the full capabilities of the meter, they can have little reasoning to support their recommendation.
So how do you really determine the best multimeter that’s available?
The answer is simple.
Some electricians will swear black and blue that you need this particular brand*, or that particular feature, but when it all comes down to it - you need a multimeter that is designed for the type of work you’re going to be doing with it. The best multimeter is the one that is best for YOU. For YOUR requirements. The best multimeter for you, may not be the best multimeter for Bill the domestic electrician, or Tim the industrial electrical technician, or Matt the HVAC guy.
* Of course brands will still come into your decision making - I'm by no means suggesting that brand isn't important. Making sure you choose a quality brand is imperative! And while cheap, no-name meters with certain specs and features may at first appear tempting, it's important to keep in mind that not all meters are made to the same level of quality and reliability.
In short - brand IS important. It's just not necessarily the best place to start when making your decision on the best multimeter for you…
And while I could easily tell you that the Fluke 179 is the best multimeter, or the Gossen Metrawatt M246C is the best multimeter, and have you go and invest your money into one of these products - and don’t get me wrong, these meters are definitely GREAT products! - the question remains, are you buying the right meter for YOU? Will it do what you want, or have you bought more than you require? If you always take the freeway, a scooter’s not going to cut it, and there’s no point buying a Ferrari if you're always driving dirt roads.
Having said that, due to popular demand, we have put together a list of the best multimeters available for 2020. Check it out here, but again, keep in mind that the BEST multimeter is really going to be different for every person, and depend on individual requirements – and that’s what this article is going to show you.
How to find the best multimeter...
It’s actually pretty straight forward.
You start by asking yourself three initial questions.
They are (in order of importance) -
- What do I need the multimeter to measure?
- How accurate do I need the measurements?
- Where (in what environmental conditions) will I be using the multimeter?
Only after considering each of these, should you start to consider brands and budgets...
Now let's look at each of these questions in more detail.
WHAT do I need to measure?
Firstly, consider what you need to measure with your meter...
Is it Voltage? Current? AC? DC? Or AC + DC? Perhaps alternating voltage, or currents with a lot of noise?
Do you need functions other than voltage and current measurements? Perhaps capacitance, diodes, frequency, duty cycle, resistance, temperature are required? Maybe even specialist measurement such as milli-ohm, insulation, dwell angle etc?
Taking this into consideration first, will help you get started with your meter selection.
And keep in mind - finding the meter that will suit your requirements doesn’t have to be difficult. In fact, the Delta Pro filtering system is designed to make this whole process easy and painless for you.
If you are a home hobbyist and just looking to start out, then we recommend you have a look at this home and hobbyist collection of meters. It has a range of reputable brand meters that have most of the functions you’re likely to need.
How accurate do I need the measurements?
Of course, if you’re going to the effort of taking a measurement, there’s a certain expectation that the results shown are going to be 100% accurate. At least, with a GOOD meter, the results would be 100% accurate, right? Well, funnily enough, this is not the case.
When investigating meters, you will find that each come with a stated degree of accuracy from the manufacturer.
And while the degree of accuracy of a meter may not be critical for all meter users, it’s certainly not a feature that should be overlooked.
A meter that is accurate to within 1 - 2% is common for multimeters in the mid to low model ranges. If you only require reasonably accurate figures, then meters with these accuracy ranges are a good start. Perhaps you are checking currents on a three phase distribution board, to see if the circuits are reasonably balanced. Here, accuracy to within 1 - 2% would suffice.
However higher accuracy may be required for some trouble shooting or professional readings. In which case, you may need to obtain a meter with higher accuracy (eg. accurate to within 1%). For example circuit board trouble shooting, or certifiable test results from measurements taken, may require these accuracies.
Some meters not only have high accuracy in their specifications, but come with a calibration guarantee or certificate to ensure this accuracy.
Accuracy to within 1% would be considered great accuracy, and less than 0.1% is excellent accuracy.
However, the accuracy of your results is also impacted by the count, resolution, and range of your meter. It’s one thing to have a really accurate meter, it’s another thing for the meter to be able to actually display those results to the user.
In short - count, range and resolution are all related, and dependent on each other. The count and the range are dependent on what the circuitry in the multimeter is capable of measuring. The resolution is how many significant figures the result will be displayed in. And the amount of significant figures, is dependent on the count. If you feel like you’re thinking around in a circle, you’d be right!
When the circuitry in the meter gets to the maximum value that it can measure in a range, a new circuit must then be introduced to continue to measure higher values. This new circuit which is for a higher range, will result in a loss of resolution (significant figures) by a factor of 10.
Let’s look at an example… A multimeter has a count of 2,000, and current ranges of 2A, 20A, and 200A. The resolution will be different for each range, and is determined by the count of 2,000.
2A – has a resolution of 0.001 (3 significant figures). The maximum displayed result in this range will be 1.999.
20A – has a resolution of 0.01 (2 significant figures). The maximum displayed result in this range will be 19.99.
200A – has a resolution of 0.1 (1 significant figure). The maximum displayed result in this range will be 199.9.
If your meter has autoranging, it will automatically put your meter in the correct range for what is being measured. If your meter is manual ranging, you will need to select the correct range for what you are measuring.
If you attempt to measure higher than the range you have selected, or higher than the capability of the meter, your meter will display OL (meaning Over Limit).
So when considering your accuracy requirements, make sure you look at stated accuracy, count, resolution, and range.
In what environmental conditions will I be using the multimeter?
Now you need to consider where and how you’re going to be using your meter.
What application category rating (CAT rating) do you need?
What weather and dust conditions do you need to operate the meter in?
How battered is the meter likely to get? How tough is it? What warranty comes with it?
After all, if you’re working in an environment where there’s lots of water, or where you know there’s a risk of the meter being dropped from a decent height, (or possibly, where there’s a risk of the meter being dropped from a decent height and landing in a body of water!) then this is also going to come into your decision making when choosing the best meter for you.
Of these three environmental considerations, the CAT rating is the most important. You need to ensure that the insulation of the tester will not break down if a transient high voltage occurs on the system you are testing. For more information explaining CAT ratings, see our CAT Rating explanation.
For example, if you’re a home hobbyist looking at using your meter on circuit boards, or on the wiring of your caravan, you may only need a CAT II rating. However if you’re working on an industrial distribution board after the supply meter and associated circuits, you’ll need a CAT III rating or higher.
After deciding on the CAT rating you need, consider the IP rating. Paying attention to the meter’s IP rating will ensure the meter is appropriate for the dust and moisture the meter may be exposed to. The IP ratings are usually listed in the manual or specifications sheet. For more information explaining the different IP ratings, see our IP Rating explanation.
The best IP rating your meter can have, is IP68. An IP68 rating indicates your meter is both water and dust proof. This is something that would be incredibly helpful if you’ll be working in a mine, or on boats or marinas.
If you know that your meter is likely to get beaten around a bit, then you’ll want a meter that is tough and durable. Meters can come with an outer skin that is designed to absorb some degree of impact, making them more rugged. Some will come with a protective case for extra protection during transit and storage (these cases can be part of the package or an added option, depending on the manufacturer). Sometimes, a drop test height can be included in the specs.
Finally, warranty may be a consideration. The length of time offered as a warranty does vary between manufacturers and models. 12 months to 3 years are common warranty periods, but some do offer a limited lifetime warranty.
And the BEST multimeter is...
The best multimeter is not necessarily the brand or model that you have used in the past or been recommended. It is the multimeter that measures what you need, has appropriate accuracy and will be safe and suitable for the environment you are working in. Once you have come up with a short list from these requirements, you can then concentrate on brand and price.
DeltaPro have a comprehensive filter searching system to help you find the best multimeter. It is easy to use and narrows down your search results to only those quality brand meters matching your requirements. Once you have this short list, your choice of meter will be so much easier. And you can be confident that you will have chosen the BEST multimeter for you.
~ Delta Pro are Authorised Stockists for othese Quality Brands ~