Clamp meters – Buying guide & Comparison
If you’re interested in finding the best clamp meter for your needs but don’t have enough time to go through our buying guide and product descriptions this short paragraph should prove helpful. After consulting dozens of clamp meter reviews the product we found to rise above the rest is the Fluke 323. For those in the know, the company name itself should be an assurance for good accuracy and reliability. The 323 also comes with True RMS which is a must for taking accurate readings of nonlinear loads in any waveform. Besides this, it can take non-contact readings for AC current to provide an extra measure of safety, and its wide clamp opening of 30 mm can fit any wire. If the fluke model is unavailable, or you are interested in even more features, then the Uni-T B4Q094 UT210E might be the right choice for you.
If not an expert in the field of electrical engineering, finding the best clamp meter for your needs might be tough since these are rather complex measuring tools. To come to your aid, we’ve compiled a short list of things to look out for when making a choice.
Clamp meters measure a number of parameters of electrical current by taking readings of the magnetic field around a wire. Most models can also act as thermometers if fitted with an adequate probe.
The primary measurement taken is AC current, usually up to 400 amps, with some models being able to work with DC as well for added functionality. Voltage for both AC and DC can go as far as 600 V for units rated to work on Cat III electrical installations. Resolution (i.e., the maximum sensitivity of the measurement) is somewhat important when it comes to voltage
Crest value tells you if a given circuit is overloaded. This is determined by the waveform’s peak value compared to its RMS value. Only units with true RMS can take this measure accurately, and without it, the reading can be off by as much as 40V(!). Unquestionably, this is a great feature to have.
Continuity refers to whether the circuit is open or closed, the best clamp meters for electricians usually give a continuous auditory signal to let the user know that the wire is live. This prevents display clutter and adds an extra measure of safety.
Resistance is measured in ohms and refers to the “ease” with which electrical current passes through a given conductor. Ranges for most units vary from tens of milliohms to kilohms into the single digits. Resolution is also important here with the best digital clamp meters being able to make distinctions of as little as 1 or 2 milliohms.
A very important safety feature to have is a non-contact voltage detector. This alerts you, usually through a noise signal, if live current is passing through a wire nearby before you get too close to the installation.
While not as important, auto-ranging could prove useful when working with an unfamiliar wire. Usually, the operator has to set the ranges he expects to work with around, which might add a few minutes to the whole task, but with auto-ranging, the tool does that for him.
Most clamp meters only measure AC current, commonly employed for generators and in the national electrical network. DC current is typical for batteries, from those that power cars to regular AAs and having a clamp meter which can measure DC can sometimes prove useful. Consider if you’ll really be needing it before buying since some of the better models might be lacking this feature.
The unit should be small and easy to carry since it will compete with a relatively high number of similar appliances for space in the toolbox.
Check that the buttons are firm and easy to push, even when wearing gloves, that the dials aren’t so easy to turn as to do it accidentally and that the display is clear to read and backlit. Many times you’ll be working under sunlight, and nobody likes squinting to see a reading.
Nearly all models have the ability to retain the latest measurement in case you need to check it out at a later time. This is obviously useful, and it’s good to have a unit that can hold more than one measurement to memory to give you the possibility to compare between them without taking your own notes.
You can account for things like durability or resilience mostly by checking the history of the brand you’ll be buying. In the clamp meter world, there are few manufacturers as well regarded as Fluke. We rarely recommend a particular brand, but the name Fluke just pops out in consumer reviews and specialist guides too often for us not to take note.
Top clamp meters reviews in 2018
To make it easier for you to decide on what to buy we compiled a shortlist of suggested products, selected for their functionality and performance, as well as customer response and rating on retail sites.
A product of the famous Fluke manufacturer, the 323 promises a lot and judging by what its many satisfied users have to say, doesn’t disappoint. It seems to be overall accurate and reliable, with a measurement accuracy of just +/-2% and good resolution when reading ohms.
Its salient feature is the true RMS sensing meter, which allows it to measure both linear and non-linear loads of any waveform. Like most other clamp meters on the market, it’s rated for CAT III installations up to 600V and CAT IV installations to 300V and can take measurements of AC current up to 400 amps. It can only take voltage readings of DC current, however, but its range when measuring resistance is somewhat impressive at a maximum of 4 kilohms.
For added safety, it is capable of non-contact voltage detection and an auditory signal lets you know when the wire is live.
A wide jaw opening of 30 mm will allow for a great degree of comfort when taking readings off thicker conductors, reducing the chances of accidentally touching it or interrupting the circuit.
True RMS sensing meter lets you accurately measure nonlinear loads regardless of waveform.
A reported reading accuracy of +/-2% will ensure that you always get correct data on any installation you are working on.
It also has a couple of nice safety features, besides the wide jaw opening, these include non-contact voltage detection and auditory cues to keep you aware of the state of the conductor you’re working on.
The ranges for both AC current and resistance measurements are quite good at 400 amps and 4 kilohms respectively.
The Fluke 323 is rather basic in the features it offers. It only takes amp readings for AC current, only one figure can be saved to memory at a given time, and the ranges must be set by the user.
Buy from Amazon.com for ($110.07)
Uni-T B4Q094 UT210E
Despite its small size, this Uni-T model comes with an impressive array of functions. It has true RMS which makes it score well in functionality from the get go, but it can also measure both AC and DC current (sadly it has a rather narrow range of only 100 amp), capacitance, continuity, resistance, and voltage while still being able to fit in your pocket.
It does have voltage detection, connected to a small LED that lets you know the wire is live without draining away the AAA batteries. The battery level indicator will prove useful when deciding whether or not you should pack some spares.
It has pretty good accuracy and resolution, being able to measure ohms to the third decimal point and with a +/-1%+2 reported deviation.
It can also hold multiple sets of figures, the maximum, minimum, min-max and it also has a zero mode.
This Uni-T comes in a small, convenient package which makes it easy to use and to carry around.
Convenience features also include a battery life indicator, an auto power-off that activates after 15 minutes idle and the ability to hold to multiple figures at once.
Rather unusual for an item in its class, it can be used to measure capacitance (Farads) which significantly adds to its functionality.
It has good overall functionality, besides what’s been already mentioned it can measure both AC and DC current, voltage and resistance.
A well-performing unit, the UT210E has a pretty good resolution, especially for amps reading, with a minimum of 1 mA of sensitivity.
It has a rather low range for AC and DC current readings, of a maximum of only 100 A. While enough for most household needs this places it somewhat below its closest competitors.
Buy from Amazon.com for ($45.49)
This Etekcity model surprised many customer reviewers with the great functionality it offers for the price. At only a quarter of what you will spend on similar products you get all the basic functionality of a clamp meter — the ability to measure AC current, the voltage for both AC and DC, resistance, continuity, and diode testing together with some interesting convenience features that will make MSR-C600 great for hobbyists and beginners.
The auto-ranging function means that the user won’t have to pre-set the ranges he’ll be working with by himself. Simply lock the clamps around the conductor and wait for it to give you the reading. Both maximum readings and the latest reading can be saved to memory, sparing the user from having to use a pen and paper to take notes.
At this price, you won’t be getting either true RMS nor voltage detection, however, which subtracts from both the MSR-C600’s functionality and safety.
At around a quarter of the price of similar models, this Etekcity product makes for a particularly good value for the money. If you want a good model for non-professional, household use, this might be a good pick.
It has a pretty wide clamp opening, of 28 mm in diameter, ensuring that you won’t touch any wires while taking current and resistance readings.
The MSR-C600 has all the basic functions of a clamp meter in a very affordable package: the ability to measure AC current, AC and DC voltage, resistance, an audible signal for continuity and diode testing.
The auto-ranging function and the ability to save readings give it good convenience.
It lacks true RMS which makes it unsuitable for use with nonlinear circuits. Also the lack of a distance voltage detector means the user will have to use probes to verify if a conductor has current going through it.
Buy from Amazon.com for ($58.65)
Signstek Uni-t UT202A
This Signstek model is in the same price range as the Etekcity, offers an almost identical set of functions and enjoys a similar level of customer appreciation.
It can be used to measure AC current, AC and DC voltage, resistance through a diode test and continuity. The auto-ranging and data hold functions offer it great convenience, together with a low battery indicator and a full icon display.
It works under the usual ranges of 200 mV to 600 V for DC voltage and a minimum of 2 V all the way to 600 V for AC. These are the ranges for CAT II installations, for CAT III the unit is rated as safe to use at a maximum of 300 V.
The accuracy figures supplied by the manufacturer seem pretty good, and some users found it to be relatively precise when measured against more expensive Fluke models.
The UT202A offers great value for its price, being able to do most of the things a casual user would demand of it without representing a particularly costly investment.
Owners find in reliably accurate, even when compared to professional products, which makes it a particularly good purchase for hobbyists and DIY enthusiasts.
It offers good convenience thanks to the auto-ranging function and a lot of useful information, such as battery life and maximum value holding available on display. It also has a continuity signal and an auto shutdown function.
It comes together with some extra items from the manufacturer, such as a user’s manual and a specialized pouch for holding.
Like most other clamp meters in its price range, the UT202A doesn’t feature true RMS which will make it less useful for professional electricians. Most users still agree that it’s still a very useful product to have around the house.
Buy from Amazon.com for ($14.99)
Klein Tools CL800
The Klein Tools model is a professional, heavy duty clamp meter, great for both homeowners and electricians. It has Class 2 safety rating thanks to its double insulation. This means it can handle 600V at CAT IV and a whopping 1000V of electricity at CAT III.
It can be used to measure both AC and DC current, voltage, resistance, continuity, frequency, capacitance and also tests diodes — basically, everything that’s required for electrical work. In true multimeter fashion, it’s outfitted with a thermocouple probe for temperature readings.
As it would be expected, it can be effectively used for taking measurements of nonlinear loads thanks to its true RMS capabilities.
Another interesting function is the Low Impedance (LoZ) mode used to identify and eliminate stray voltages and ghosts.
Users report it to be particularly sturdy and durable and the manufacturer tested it as safe to be dropped from a 6” height.
The CL800s high safety rating and numerous features give it very good versatility. It can be used for professional work as well as household DIY.
Thanks to the true RMS it can accurately take readings of nonlinear loads, regardless of wavelength.
User convenience has not been neglected by the people at Klein, the CL800 features auto-ranging, which will spare you the trouble of having to adjust for a different range when taking readings off of multiple wires in quick succession.
It can measure for hertz and farads, which very few units in the same category or price range can do. The ability to take temperature readings will also prove useful while doing electrical work.
It has a specialized Low Impedance mode that can be used to eliminate ghosts and stray voltages.
Multiple users noted that the non-contact voltage (NCV) sensor could malfunction or stop working altogether. This can be said to only have a limited impact on its functionality since the NCV is more of a secondary safety function.
Buy from Amazon.com for ($124.47)