If you are familiar with multimeters but have never used a clamp meter, you’ll find it an ideal tool for electricians to have in their toolbox. It is essential to use the best clamp meter there is. A clamp meter is an electrical test tool that helps to measure electrical flows in wires, whether for your car, home, or machinery. It is a hybrid between a digital multimeter and a clamp.
But when do you use a clamp meter (as an electrician), and what’s the best clamp meter? There is a prime difference between multimeters and clamp meters, and that’s voltage versus current. While they each have crossed-over functionalities, the basic definition of each is that a clamp meter is a current measuring tool with some voltage abilities. In contrast, a multimeter is a voltage-measuring tool with some current abilities.
It’s important to understand the differences between them as you will need to differentiate between them when making different measurements.
How does a clamp meter work?
In the past, you would typically use test probes to measure currents. However, a clamp allows you to continue measuring wires without breaking the circuit to get a reading. This saves you time and will enable you to measure multiple objects at a fast pace.
For a clamp meter to work, you need to ensure only one current is passing through a wire, so place one wire inside the clamp. There are two different types of clamp meters – one that you clamp onto the wire and one that you place the wires inside the circular clamp. No matter which one, the clamp detects the current moving through the meter. Depending on your meter, this can be done for either alternating current (AC) or direct current (DC).
The way meter measures the current is by using different current conductors and magnetic fields. It was first discovered by Edwin Hall back in 1870.
Why is clamp meter essential for electricians?
Clamp meters are essential for electricians to determine the root cause of issues, Whether you’re trying to find out if there is current in a specific wire or if the circuit is broken. You often need to test multiple lines in a circuit to determine which part is causing an issue.
The other great thing about clamp meters is it not only can measure current but also typically have added features to measure voltage, resistance, frequency, continuity, etc. Measuring things like resistance will determine if there is something faulty in your wire/circuit that is pushing too hard against the current.
Also, measuring continuity is vital, so you know if fuses and other objects can get current from one end to the next.
It has an endless list of significant tasks it can complete for both novice and expert electricians.
Top 5 clamp meters
I know how frustrating it can be to source quality digital clamp meters, so I reviewed the five best clamp meters in the market right now. Here are our top 5 favorite clamp meters with my own personal rating and an idea of the price range. In this review, I stated the pros, cons, and essential features of the best clamp meters. It’s no surprise that Fluke is the primary one who showed up, knowing that they are currently one of the best companies on the market for electrical meters. Feel free to check their pricing on Amazon.com via the links below.
Best Clamp Meter for Electrician
OUR TOP PICK
Fluke 323 has AC measuring capabilities, including resistance and continuity measuring functionality and True RMS, ensuring you have near-perfect readings every time. Also, the measurement can be done with no contact with the circuit. This clamp meter is a great option for personal or professional electrician use.
If you want something compact, affordable, and easy to use, you should definitely check out the Fluke 323 to add to your electrician toolbox.
Overall, I felt this was a good product for the price. While it’s not going to give you a lot of the range that the more expensive clamp meters will, it can do the job most of the time. I particularly like how small it is, and the heavy plastic makes it feel very durable, which is important when working in harsh environments. It also provides speedy and accurate readings, saving time when you have to do multiple tests back to back.
Pros
- Small compact size
- High quality and durability
- Meets IEC safety standards
- True RMS
- Low battery indicator
- Easy to use
- Runs without making noise
- Affordability
- Audible continuity sensor
- Accurately measures AC and DC voltage to a maximum of 600 volts
Cons
- Display not backlit
- Not enough space in the bag for the test leads
- Lacks DC measurement capabilities
EDITORS CHOICE
This is a great digital clamp meter that provides a bit of an edge over the Fluke 323. The Fluke 324 still has the same AC-only measurement capability (lacks DC current measurement) and comes in the same compact-heavy-duty design. It’s made to ensure you get the best troubleshooting tools for most residential electrical use for determining the presence of AC voltage load on a circuit, switch, and fuse.
What it has on top of the 323 is it can measure both capacitance and temperatures, which becomes really important when dealing with HVAC situations.
The other great feature of the 324 is it has a built-in backlight for the screen, which helps in low-light situations. You can expect that with all Fluke meters, it still has True RMS technology built-in, so you don’t have to worry about any inaccurate readings or interference.
Fluke 234 is a great clamp meter for professional and personal uses due to its decent range of capabilities and great, reliable design. This is the meter that I consider the middle ground for not being too expensive and not too cheap, making it one of my number one recommended clamp meters on the market.
Pros
- Compact easy-to-use size
- Sturdy hard plastic case
- True RMS
- Affordable
- Temperature readings
- Back-lit screen
Cons
- Not enough space in the bag for the test leads
- Lacks DC measurement capabilities
BEST VALUE
By far, one of my favorite ones, but the best always comes with a bigger price tag. What do you get for that price tag increase? The Fluke 325 makes sure that you don’t need additional devices. It comes in a great small compact size still but with all of the functionality you want in a clamp meter.
You can measure in both AC and DC from 0-600 voltage. It can also measure resistance, continuity, capacitance, frequency, and temperatures making this a well-rounded piece of equipment. It also has some great built-in features like the backlight and the min/max data hold functionality.
The Fluke 325 is also built with sturdy hard plastic making it durable for work environments where it often can be exposed to the elements and is prone to be bumped on things or falling. It also is an auto-ranging meter, so you don’t have to spend time determining the proper settings as the meter will do that for you – just wait for the beep, and you’ll have your reading.
Overall, I really love the Fluke 325 clamp meter for all its range of functionality and ergonomic design. If you want a clamp meter that can do almost everything, then spend a bit extra and get this one. You will not regret it, and you’ll be happily using it for years and years.
Pros
- Best quality on the market
- Highly durable and reliable
- True RMS
- Auto Ranging
- The broad range of measurement capabilities
- Backlight/Min-Max Functions
Cons
- Price is a bit high for most personal uses
- Not enough space in the bag for the test leads
RUNNER UP
This is the most complex and thorough Fluke clamp meter on the market currently and offers the most amount of capabilities. It has the same great compact design but with a longer clamp that opens at the center-top instead to help you get into hard-to-reach areas.
You can still expect the same great True RMS measurement capability that all Fluke clamp meters have, so you have perfect measurements. Fluke 376 can measure both DC and AC as well as frequency, resistance (ohms), continuity, and capacitance.
One of the great things about the Fluke 376 is its state-of-the-art technology allows you to connect remotely to your mobile device. This will enable you to ensure maximum safety for you and ensures you can still do proper readings even in hard-to-reach places. It also allows you to upload data to the cloud to access later easily, print off, or compile data accurately. This is all thanks to Fluke’s iFlex technology/products, which includes a separate longer metered cord that you can wrap around larger cables/items to get measurements.
While this is definitely the #1 best clamp meter on the market, it’s not typically used by many people due to its very high price tag. I only suggest you purchase this if you are a working professional and handle high-quantity current measurements daily, as it may not justify the cost.
If cost isn’t an issue, this is a great product in terms of its high capabilities and advanced technology for gathering data. It also has a nice quality backlight, auto shut-off, data hold, and min/max features, so you have everything you need in one meter.
Pros
- Ergonomically built for easy one-handed use
- Slim use with longer clamp handles
- Best on the market for electricians
- True RMS
- The broad range of capabilities
- iFlex cords and technology
Cons
- Very expensive
- Probe leads are not the best due to short metal lead
RUNNER UP
I saved one of the best for last, and it’s not a Fluke brand this time! The Klein CL800 is an overall well-rounded high-quality clamp meter with so many great functions and is fit for professional use. Compared to the Fluke brand, the Klein tools can measure DC and AC along with resistance, capacitance, and frequency for the same price.
It also has the same True RMS and Auto-ranging functionality and can measure resistance, capacitance, frequency, continuity, and diode tests. Another surprising thing is that it can do temperature measurements with its thermocouple probe and can go into a low impedance mode to detect any ghost voltage. The Klein tool also has a high safety rating.
Overall, the CL800 has the most amount of measurement capabilities for a clamp meter for its affordable price. While you don’t get the Fluke brand, you still get all of the rest of the great qualities in one device.
Pros
- True RMS
- AC and DC measurements
- Durable rubber coating
- Temperature thermocouple probe included
- Starts reading automatically
- Voltage detection
- Ideal for professional electricians
- Resistance, continuity, capacitance, and frequency testing
- Measures different range accurately
- Backlit display
Cons
- Screen resolution issues at angles
- Slow to process auto-ranging measurements
Frequently Asked Questions
Here are some key points to know when handling clamp meters.
How to measure a voltage with a clamp meter?
If you want to measure the voltage of a specific wire, set your clamp meter to the voltage (V) setting and select the appropriate volts measurement. If you are unsure, you can simply select the lowest and move up from there.
Connect the black probe to the COM jack and insert the red probe into the V/O jack. Touch the metal probes to the object (fuse, wire, etc.), and you'll get the reading on the clamp meter's screen.
How to measure AC and DC with a Clamp meter?
Measuring either AC or DC can be done quickly and easily using your clamp meter. First, ensure you disconnect any probes that are plugged into the device and then turn the dial on the meter to either the proper AC or DC function.
Ensure you press the zero key before making any measurements to validate that there is no current in the device. Press the jaws on the clamp meter to open them and put the wires inside. Wait a few seconds until your clamp meter beeps (if on auto-ranging), and you'll have your measurements.
What is an NCV clamp meter?
NCV stands for a non-contact voltage detector, which basically means that you don't need the device to be touching anything for it to get a reading. A clamp meter that can do this kind of measurement is very important to have in case you are unsure if a piece of metal, fuse, wire, or anything else has a current running through it.
The NCV functionality ensures your safety when working around loose wires, which could electrocute you.
What is true RMS?
True RMS (Root mean square) is what many people call the "effective value" of a voltage or current. While there are many different ways to effectively measure current or voltage, most inexpensive meters use an averaging technique to determine the RMS reading of a voltage or current. This type can give you accurate measurements under perfect circumstances/environments.
If you don't have a perfect scenario, then True RMS is needed as it takes the square of the value and averaging it over time, then displays the average's square root. While this may not make as much sense to most people, the vital thing to remember is that a meter with True RMS will ALWAYS give a more accurate reading and is definitely worth the money.
How to measure milliamps with a clamp meter?
Measuring milliamps on a clamp meter can often be done as long as the clamp meter can display in milliamps. Check first on your user manual if your clamp meter can measure milliamps, and then you'll be able to move forward. Typically, multimeters that can read milliamps will come with a much smaller clamp/jaws to do this.
How to measure kWh with a clamp meter?
To measure kWh with your clamp meter, you'll first measure the current through the conductor/wire/fuse (same steps to do this with a multimeter too. Once you have the measurement, it's a simple division of 1000 to get instead.
What is the NIST-Traceable Calibration Certificate for Clamp meters?
Calibrating your clamp meter and multimeters is vital to do at least once a year (or more, depending on how often you use it). Typically, you will not have the proper instruments to calibrate the device yourself; thus, it's important to find a vendor who can calibrate it for you.
This is where the NIST-Traceable Certificate comes into play in the professional arena; having the Certificate is extremely important to show that your measurements are precise.
Vendors who complete NIST-Traceable Calibration certificates use highly-accurate multi-function calibrators and standards as per the manufacturer's recommended procedure.
How to measure amps with a clamp meter?
If you're looking to measure amps (or current) with your clamp meter, then you'll need to follow a few simple steps. Before you start finding the current on a specific wire or device, you'll want to know what the item should have flowing through it by looking at the object's tag/sticker.
Then search for the power cord that powers the device and then set your clamp meter to the appropriate range (depending on what you found on the object tag. Open the jaws of your clamp meter and place the wires inside of it. You'll need to ensure the clamp meter's jaws completely close so that a proper reading can happen.
Wait for the clamp meter to beep or complete its function before you write down the reading. Typically, when the reading no longer fluctuates, it means you have the proper reading. Once you have taken the first reading, if you need to take additional ones, you can easily do this by just moving the clamp from one wire to another.
Wrap-Up
These are the best clamp meters for electricians in the market, and for a good reason. Although you may stumble across other clamp meters out there, the most important things to keep in mind when choosing a clamp meter are performance, accuracy, reliability, and, most importantly, safety. Clamp meters are great to help you save time and effort when doing electrical work and ensure you stay efficient when doing any of your homes or work wiring objects.