Looking to get a new meter, and wondering whether to go for a multimeter or a clamp meter?
Although these days a lot of clamp meters and multimeters offer similar functions, there’s still some key differences to be aware of.
Multimeters versus Clamp meters
A multimeter is as it sounds.... a meter that is able to do more than just one type of measurement. They are usually capable of a multitude of measurements.
Most will measure at least AC/DC voltage and current, frequency, resistance, continuity, capacitance, and diodes. Depending on the model, meters will come with extra specialty functions, for example duty cycle, 4-20mA percentage conversion, data logging, insulation testing…. and the list goes on. The measurements they take are usually pretty accurate, and the better the specs of the meter, the more precise they are (and resolution begins to get better as well).
While a multimeter does excel in very small currents, such as electronic circuits, they are quite limited when it comes to measuring higher current. The majority of multimeters are limited to 10A continuous measurement, with some being able to handle 20A for short periods. When either of these limitations are exceeded, the usual result is a blown fuse in your meter.
Also something to be aware of - a multimeter measures current directly. In order to do this, you need to break into the circuit you wish to measure, and place the multimeter in series within the circuit. Which, as you can imagine, is not always ideal! Sometimes you may just want a quick measurement, without going to the effort of breaking and rejoining wires. Or perhaps you’re working with higher currents, and not practical to break into the circuit at all!
A clamp meter (also referred to as an amp clamp), in the traditional sense, is mainly concerned with current measurement (amperage). The range of currents they can measure can vary from micro-amps to 1000’s of amps.
A clamp meter does not measure current directly. Instead it measures the magnetic field that is produced by a current, and displays the value of the equivalent current that would cause a magnetic field of the strength that is being measured. To do this, a circular sensor is clamped around a cable of the circuit being measured. It’s fast and simple, as you do not need to break into the circuit to take a measurement. There is also no risk of blowing a fuse, as the meter is not measuring current, but magnetic field. As long as you’re able to get your clamp around the conductor, (which admittedly, can be difficult in cramped, tight areas), clamp meters require very little effort on the part of the user to get a current measurement.
Nowadays most clamp meters are multimeters as well, and usually have at least voltage, resistance, frequency, continuity, capacitance and diode testing capability.
So which one?
Understanding the difference between the 2 meters, makes deciding on one relatively easy. Do you need to measure current greater than 10A, and do you care if you have to break into a circuit for currents less than this?
Current is one of those measurements that, depending on what you are doing, will either be measured often for specific tasks, or very little if not at all. If you are not regularly measuring current, or the current you would measure is very small, particularly with electronics, then you are better off with a multimeter. It will measure small currents very accurately. It also comes with multiple other functions, and performs them very well.
If you are going to be regularly measuring current, and these currents are more than 10A, then a clamp meter is the better choice. Even with currents less than 10A, clamp meters measure current without breaking into the circuit as mentioned above, hence may be a more practical solution. And with the clamp meter, you will most likely still get the basic measurement capabilities of a multimeter, such as voltage, resistance, continuity, and perhaps a few others.
Now that you’ve worked out which one best suits you, here’s links to our collections to get you started...
If you know you require specific functions or capabilities, make sure to use the filtering system on these pages, to help narrow down your selection.
One last point which might sound contradictory, and for many users is not an issue. You may be looking for a specialised function that a multimeter may offer, but you also need the current measuring capability of a clamp meter. There are two possibilities here.
1. Some multimeters have the ability to attach a clamp measuring tool to the multimeter. In this instance you can purchase the attachment and use it in combination with the multimeter. But not all multimeters will do this, so some investigation here is required. Further to this, an inherent added error will be introduced to the accuracy with the attachment, so if accuracy is a requirement, this should be investigated to see if it will suit your purpose.
2. You can find a multimeter that has the required specialty function, and purchase a clamp meter as well. This is my preferred solution, as the clamp meter will come with other basic functions, allowing most jobs to be done with just the clamp meter, and only requiring the multimeter when the specialty measurement is needed.
You can find more general information about multimeter capabilities here.