Buying guide for best multimeters
At first glance, a multimeter seems like a tool that only professional electricians and electrical engineers would care about. But to the experienced do-it-yourselfer or hobbyist, the multimeter is an indispensable asset to the home toolkit.
Unlike an AC voltage checker, which simply tells you that an electrical current is present in wiring (an important safety check), a multimeter gives a precise measurement of voltage and current for many types of electrical circuits – that’s why it’s called a “multi” meter. This enables the user to determine wiring capacity, or ensure that current is traveling through a circuit in the expected, safe way.
Of course, there are many multimeters to choose from. Which will best serve your purpose? At BestReviews, we guide you through the buying process to find the multimeter that meets your needs. If you’re ready to purchase, check out our recommendations in the product list above. Or, for more information about comparing multimeter brands and models, read our shopping guide, below.
Safety
When working with any electrical component or equipment, safety is absolutely paramount. A multimeter is simply test equipment, and it won’t protect you from electrical shock.
Follow safety procedures when working with electricity at any voltage. Make sure that you won’t accidentally “ground” when working by wearing appropriate gear (sturdy, non-conductive shoes, clothes that won’t interfere with the work you’re doing, protective, non-conductive work gloves) and using tools that are rated for electrical work. Your tools should also have non-conductive grips. Always double check your work, and never be careless around wiring or circuitry.Working with AC (alternating current) can be especially dangerous. This is the kind of current used in your home’s wiring. Only those with experience and skill should use a multimeter on or work around AC circuits and wiring.
Most multimeters are digital models that provide clear readings on a screen. Digital models offer great accuracy and often have a handy auto-ranging feature. We evaluate many digital models to find the best on the market.
Handheld multimeters are designed with a selection dial and three ports. When researching handheld multimeters, we look at basic models as well as more advanced choices.
When assessing the value of a multimeter, we consider whether it comes with necessary accessories such as wires, probes, and batteries.
When assessing the functionality of a multimeter, we consider the clarity of its display screen and overall ease of operation.
The amount of current you expect to be reading is an important consideration when choosing a multimeter. In our evaluation process, we consider the voltage range options for each model.
A quality multimeter should allow you to switch between AC and DC voltage settings. We look for these settings and consider their ranges when evaluating multimeters.
We examine multimeters that are best for hobbyists as well as more advanced multimeters, thinking about who would benefit from each model.
In addition to core functionalities, we consider whether a multimeter offers other useful functions and features, such as autoranging, temperature probes, and amperage measurements.
A good multimeter should be built to last. When we evaluate multimeters, we assess durability and quality of construction.
Accuracy and reliability are crucial features in a multimeter. We conduct thorough research to find models that stand out in performance and reading accuracy.
What is a multimeter?
A multimeter can measure voltage, resistance or current in a wiring circuit. This makes it a key part of diagnosing circuitry problems. For example, if a light switch in your home has to be replaced frequently, or if a fuse in your car keeps blowing, an electrician may use a multimeter as part of the diagnostic process to test how well current travels through a circuit. They can also determine whether there is resistance within a circuit, and measure the voltage or amperage.
For hobbyists – for example, if you’re building a circuit board – the multimeter can test circuits to make sure they’re powered at the correct voltage.
More advanced multimeters offer additional measurements such as microamps, decibels, rotations per minute, even temperature and humidity.
Learning to use a multimeter can be fun and give you a fascinating look into how circuitry works.
Caution
Never use damaged test probes. Check them before each use, and replace them if they are bent or otherwise damaged.
STAFF
BestReviews
Key parts of a multimeter
Display
A digital or quartz crystal display on the front of the device shows alphanumeric symbols (1, 2, 3 and ABC), up to at least four digits, as well as a negative sign.
Selection dial
A large knob in the center of the multimeter, usually below the display, with a number of different measurement settings.
Ports
Connection points, usually located at the front of the multimeter, where one end of the multimeter’s probes are attached. One port will always be marked “COM,” which stands for “common,” and is connected to the ground (or negative) probe.
Wires
Multimeters come with at least one red and one black wire. One end of each wire has a connector which fits into the ports on the multimeter.
Probes
The other end of each multimeter wire is connected to a probe. There are several types of probes that can be used with a multimeter, but the most common ones in use include alligator clips, which work well when testing circuits on a breadboard, and test probes, which are simply held against each end of a circuit (and are also inexpensive to replace). Many multimeters come with multiple probe types that can be quickly attached to the wires.
Types of multimeters
Digital: The most common type of multimeter on the market today, these offer an easy-to-read digital screen.
Analog: This older type of multimeter displays its readings via a needle over a chart of measurements. These can be much harder for the layperson to read, but many users find them to be easier to use when working with highly sensitive measurements.
Single probe: Most often seen in AC voltage detectors used to test current.
- Clamp: Used by electricians to more safely measure AC current, this single-purpose meter clamps around a wire to measure the current. Clamp meters must have a rating that matches or is better than the wire being measured in order to be used safely.
Models and prices
- Pen: These compact, pen-shaped multimeters (which actually look more like futuristic screwdrivers than pens) can be held in one hand and have a single test probe for non-contact AC voltage detection. They have limited functions, and they’re among the lower-priced multimeters, ranging between $27 and $40.
- Handheld: The most common type of multimeter, most have a boxy, rectangular shape and are pretty simple to use, with a large selection dial and three ports. Handheld multimeters can be purchased for as little as $10 to $40, with high quality models retailing between $66 and $190.
- Bench or box: These high-end multimeters are used by trained electricians and engineers to test a much wider range of circuitry. They have more ports and a larger setting selection, as well as a much more robust digital (or even LCD) display to show more detailed readings. These start at about $300 and can reach $1,500 or higher.
What to look for in a multimeter
A good multimeter should offer three key features above almost everything else:
The capability to select voltage ranges
Ohm (resistance) measurement
The ability to switch between AC and DC voltages
Determine what you’ll need from a multimeter before your purchase. Are you working with computers? Having a multimeter that reads DC current is important. If you’re working with AC wiring, then a multimeter that reads AC current is essential.
Know how much current you will typically be reading, also known as the tolerance range. For example, if you’re testing a 12V DC power supply inside a computer, the multimeter you’re using should have a setting for that range. (Typically a 12V circuit is measured using 20V setting on the multimeter, which allows you to measure circuitry up to 20 volts, but no more than that.) If you’re testing 120V AC wiring, the multimeter must be set to that tolerance.
Most handheld multimeters have AC and DC settings in the ranges typical to most common computing, auto repair and DIY needs. However, always check those settings closely to be certain that the multimeter has the ranges that you need for your repair or build project.
An ohm measurement capability is important to measure continuity vs. resistance within a circuit. For example, if a wire is broken and no current is passing through it, the ohm reading on the multimeter will indicate “infinite” resistance. If a wire is good, current will pass through it and very little resistance will be indicated when using an ohm measurement setting.
Other features that are nice to have, but not as important. Some of these include:
- Autoranging: This feature automatically changes the multimeter’s range to the setting that best matches the circuitry it’s measuring. It can be handy to have, but less experienced multimeter users may not be able to get the most out of this feature.
- Temperature probe: This is helpful for measuring the temperature of certain electronics or the temperature inside a computer case, which can help when trying to diagnose certain circuitry problems. It’s not strictly necessary for most common multimeter applications.
- Amperage measurement: Some users do need to measure amperage, but in many cases, particularly when working with computers, this setting isn’t needed.
FAQ
Q. What’s the best way to tell if a multimeter is right for the job I need it for?
A. If you know the voltage range you’ll most often measure, check the multimeter’s maximum voltage rating and current rating. These should be higher than the voltage you plan to measure – otherwise you can damage the multimeter, or you could even sustain an electrical shock.
Q. A friend told me if I don’t set the multimeter to the right setting after each use, I can break it when testing a circuit. What does that mean?
A. Each time that you finish using a multimeter and prepare to put it away, put it into a “friendly” mode. That is, connect the probes to the multimeter in the “read voltage” configuration (if you changed their configuration to current mode, for example), and set the dial to read DC voltage. Because users tend to quickly grab the multimeter to measure voltage, this ensures that you don’t accidentally complete a circuit in the wrong mode, which can damage the fuse or the multimeter.
Q. Do the red and black wiring colors on the probe wires really matter?
A. They can be useful when measuring voltage, since black wiring usually signals the “ground” wire or “common” wire in electrical work. When measuring current, it doesn’t matter what color the probe wiring is, but sticking with the “black wire means ground, red wire for live” guideline is a good practice.
Q. How useful is the autoranging function on a multimeter?
A. Autoranging is sometimes listed as a selling point on lower-priced multimeters, but its usefulness depends on the skill and knowledge of the user. Autoranging multimeters automatically change shift to the most appropriate range for the application. However, it doesn’t make a multimeter easier to use – especially if measuring voltage or current that is fluctuating. In that case, switching the multimeter to manual mode works better.
