Multimeters and clamp meters can both serve similar purposes as useful tools when trying to determine electrical current. You may find yourself uncertain as to which of these to choose. While they both have their pros and cons, you may find one more useful than the other depending on your given situation.
There are a few key differences between multimeters and clamp meters when it comes to measuring current. One of the biggest being that clamp meters have the capability to check the amperage of a closed circuit, while multimeters can only check the amperage of an open circuit.
The functionality of a multimeter is done by applying positive and negative connectors, or leads, to a given circuit directly onto two exposed areas. A clamp meter is operated by opening a clamp and closing it around a wire. It’s important to note that you must only test one wire at a time with a clamp meter. Multiple wires will cancel each other out and give you an incorrect reading of amps.
There are two different types of clamp meters to choose from. One is a current transformer, which has a magnetic core and is used exclusively for measuring alternating current (AC) like what you’d find in your wall socket. The other is a hall sensor, which can be used for AC and direct current (DC), which is a non-fluctuating current like you’d find in a battery. The latter is significantly more expensive than the former.
Clamp meters are easier to use than multimeters, and they’re faster since all you have to do is close the clamp around the area to be measured. The drawback is in the accuracy. Clamp meters do not provide an exact measurement. It converts units, providing a translation. They can, however, measure currents that are much higher than what is capable of a multimeter, with the potential to measure thousands of amps.
When measuring DC with a clamp meter, it is important to remember to zero out your meter, adjusting the device so that the display screen reads zero to ensure an accurate reading.
Multimeters can also be used to measure current, but on a much small scale, usually only allowing measurement of up to 10 amps. As mentioned before, this has to be done on an open circuit, which has the potential to be dangerous and not as quickly performed.
Multimeters will give you a reading that is more accurate, as your getting direct units that are not converted. If you need a more precise measurement, and you’re working on something with a smaller current, a multimeter may be the better tool.
In addition to measuring AC and DC amperage, multimeters can measure voltage, resistance, and continuity, which can prove helpful for a variety of jobs when you need more than just a reading of the current.
While multimeters and clamp meters have differences that make them stand out, there are combinations of products and adaptations that can allow you to have the best of both worlds with one product, or at least bridge the gap a little with one device.
Some clamp meters come equipped with leads, allowing them to perform the same functions as a multimeter with the ability to measure voltage, resistance, and continuity as well. This is in addition to the quick access and safety of reading AC or AC and DC amperage.
Alternatively, there are clamp meter adapters for certain multimeters, allowing a clamp to be plugged into the lead slots of your multimeter to provide a clamp meter reading to appear on the digital display screen of your multimeter.
Which to Choose?
Regarding which to choose, it all depends on the job at hand, what you feel comfortable with and what you need, specifically.
Both have their benefits and limitations. Therefore, there are situations that call for both. Clamp meters are more expensive, but provide a much greater range when measuring currents.
Examine the specific job, using this guide to find the tool that best fits your needs.