Clamp Meter vs Multimeter – Which is Best for Your Needs?
Which is better, the clamp meter or the multimeter? The answer is “neither,” but rather that you need to pick the tool that best corresponds to the task at hand. While there is some overlap regarding what these tools can do, there are significant differences that can make your task easier or harder, depending on which kind you get.
From the outside in, clamp meters might look like magic. You clamp them around a cable, and they can tell you what’s going on inside of them without being in direct contact with the current. However, they’re just working based on the well-understood properties of electromagnetism. The electrical current in a cable creates a magnetic field around the cable. By measuring that magnetic field, a clamp meter can tell you, at a minimum, what the voltage, resistance, and current are.
Better models can tell you things like the continuity, capacitance, and frequency of the current. Others can log the measurements for later review, which can be useful if you need to diagnose a problem but can’t stand by the clamp meter for the duration of the measurement.
Most clamp meters can measure currents up to 10A. Above that level, you run the risk of blowing out the internal fuses. However, some models come with a plug-in accessory that allows you to measure bigger amperes, though in some cases you may have to purchase it separately.
Regarding accuracy, most clamp meters can measure down to the tenths or hundreds of a unit, which is sufficient for most electrical tasks. Since they never come directly in contact with the electrical current, they’re very safe tools so use.
A multimeter can record voltage, ohms, and amperes, and most modern digital units have a resolution down to the millivolt, milliohm, and milliampere, which means they’re capable of very precise measurements. The multimeter features wires that you place in direct contact with the circuit that is you’re measuring, which leads to a greater degree of accuracy.
Of course, that increases the danger of using a multimeter relative to a clamp meter, but you can mitigate much of that danger with proper training and the use of safety equipment.
High-end multimeters can measure more things than clamp meters, including temperature, inductance, capacitance, frequency, relative humidity, and even acidity. This wide range of measurements makes them more versatile tools with more potential uses.
Analog multimeters used to go by the name “VOM,” which stood for “Voltage-Ohms-Amperes.” Modern digital models tend to go by the abbreviation “DMM,” which stands for “Digital Multimeter.”
Digital multimeters tend to be more expensive than analog multimeters, though they also tend to be more accurate. Multimeters also rise in price if the number of things they can measure increases, or if they have a larger range of measurement. The best models can cost thousands of dollars, though you’re unlikely to need one that expensive for common household tasks.
Clamp meters are generally safer than multimeters, as you don’t have to connect them to the electrical circuit. However, multimeters can generally make more precise measurements, as they must come in direct contact with the circuit. Multimeters can also come with a wider range of measurements, though the price tends to be higher on these models. Which kind you should get is largely dependent on what kinds of tasks you need to do, and which of these tools will better perform in those situations.