An Electrician's First T&M Purchase

An In-Depth Guide to Making Your First Test & Measurement Purchase


What is a digital multimeter, and why is it a necessity for all electricians?


Which one should you buy?


How much should you spend? What should be avoided?


We consulted some top electrical training instructors about what their advice would be to young tradespeople making their first test & measurement purchases and got the scoop on what the best options are.


Be warned - this may get technical! However, the answer may be simpler than you think…and it comes with the simpler disclaimer: it depends on what you plan on doing in your electrician career path.


Functions of Meters


To jump right into it, it’s critical to understand what a meter does. They’re simple diagnostic tools that accurately measure voltage, amperage, and continuity. These devices are used in the testing, install, and repair of electrical components of all capacities. Combined with our specialized knowledge as electricians, we can determine if faults exist, verify proper circuit functionality, keep infrastructure up and running, and above all else: prevent unsafe situations.


So what’s the best one to get?


  • Short answer: it really depends on what you do as an electrician and where you plan to use it. It’s safe to consider this type of tool an investment.
  • Long answer: your work environment - now and in the future – is the greatest determining factor when choosing which meter to buy. Getting something future proof for your career path is important. Will you be working only in residential settings? Or plan on being involved in work with industrial, high-current applications? Lineman, commercial, and industrial electricians all require different tools rated for their particular application. It’s safe to consider this type of tool an investment since you get what you pay for, so it’s important to choose wisely based upon your career path.


Meter Types


The capacity at which a meter can measure and the way they go about it may be different, but their function is straightforward. There are situations in which probes are necessary, and actual physical conduction is needed in line of a circuit to take a measurement. However, many measurements are made without breaking the circuit, which is the benefit of a clamp-on meter or fork meter, which are able to measure the electromagnetic field around the conductor to make a reading, making them far more useful and much safer in many applications. Many clamp and fork meters also include probes as well for situations where direct conduction is needed.


Some broad categories of meters you’ll see on the market:



These meters are used for everything from small electronics applications to battery testing and continuity assessments.


    Fork Meter

A two-pronged “fork” fits around the conductor and takes a measurement without interfering or breaking the circuit. Particularly useful in higher voltage environments and space-saving areas.


    Clamp Meter

A retractable clamp fits around the conductor that is being measured, allowing isolation from other contacts. More suited to applications in which conductor isolation is necessary, or for convenience’s sake in the work environment.


    Non-contact Meter/Plug-in Meter

A specialty meter that is typically only useful in situations where only the presence of voltage or current is being measured, to provide a “starting point” for electricians. These meters simply verify the existence of electricity in a particular circuit or conductor. Non-contact meters do so without any conduction and can be a complimentary tool. However, most instructors discourage this as being a primary tool.


Advantages of Picking the Right Meter


            One of the most obvious benefits of choosing the correct meter is safety. In high-current applications, a clamp or fork meter is clearly less risky to use than a multimeter that uses probes, as it is not necessary to break the circuit to take a measurement. There is always a potential for an arc flash when interrupting a circuit, so it’s important to eliminate the need to do so unless absolutely necessary. 


            Clamp meters also may be easiest to use in situations in which an electrician may have to isolate a single conductor from an array of others. However, fork meters may be even more useful still in tight situations, where the prongs are able to fit around conductors without having to manipulate the clamp. Some manufacturers even offer a secondary display on the base of the meter to make readings easier inside a junction box. 



Features to look for


When asked, seasoned professionals will all mention their favorite features in meters. When we had the opportunity to speak with industry pros, we got a variety of answers, including: 

  • Battery Life. For obvious reasons, this is an important aspect of a meter. You don’t want to be on a jobsite with a nonfunctional piece of equipment.
  • Alert/Tone Technology. An audible notification is crucial in certain environments that are dimly lit, or just from an ease-of-use perspective. Many meter manufacturers offer this feature.
  • Clear Digital Display with backlight. Being able to see your reading accurately in challenging workplaces is critical. Single or dual displays that are legible are extremely important regardless of where your job site may be.
  • Heavy Duty. These tools are precision instruments, yet they should be tough and durable. Many manufacturers rate their meters to easily survive up to a 2 meter fall. Some offer a rubber overmold that helps with both insulation and drop protection, in addition to helping with grip and ergonomics.
  • Certifications. Professionals typically buy their gear as a lifetime investment. Most of the reputable manufacturers certify their meters to be accurate and test them prior to leaving the factory, as well as providing some sort of warranty. Some even offer third-party certifications (such as a UL Listing) to ensure their accuracy, safety, and longevity.
  • One-handed Design. A good meter is ergonomically comfortable and can be used with one hand. This is useful in a variety of situations, whether you are a lineman, industrial, commercial, or residential electrician. 




61-747 400A AC/DC TRMS Clamp Meter with TightSight Display, torch  and non-contact voltage test function plus temperature

True RMS Rating


When a meter is accurate enough to read an entire sine wave and its potential variations, it can be rated as a TRMS capable meter. Basic RMS measurements are not entirely reliable because of potential noise in electrical systems, which may affect the AC waveform. It’s important to note that if you’re pursuing a career as an electrician, you’ll want a True RMS meter.


This is because the True RMS measurement (True Root Mean Square) uses more complex mathematical formulas that will ensure a reading that is much more accurate in real-world applications. In addition to peak values of the sine wave, TRMS meters sample along the cycle as well, making them a more precise and safer tool to use. 


Categories of Meter Functionality


Professional electricians won't bother using any meter in the field that is less than a CAT III. Many wouldn’t even begin to consider a meter than doesn’t hold a TrueRMS rating. We’ll get into both classifications here.


Meter capability spans four categories, with each getting progressively more capable but also more expensive. Superior protection ratings are necessary for more risky work environments, but these meters are also capable of readings in low-current situations as well. Test instruments are rated on their ability to withstand a voltage spike, which is applied through a specified level of resistance.


          CAT 1 - Electronic

                     These meters are useful for small electronics work, battery testing, and continuity adjustments in low-current applications. 


            CAT 2 - Residential

                        Useful in single-phase situations up to 120v, for small appliance, socket, plug-in, and long branch applications within the home. 


            CAT 3 - Commercial

                        Capable of three-phase distribution, including single phase commercial high-amperage lighting. Includes distribution devices, feeders, industrial plant circuits, and high current appliance circuitry in service areas. 


            CAT 4 - Industrial

                        The highest rating, can be used in outdoor applications of utility power, meters, distribution, overhead line, and overcurrent protection modules.


            Electricians should opt for the highest category of protection given the environment you'll will be working in - i.e., if you plan to do mostly residential work, it’s in your best interest to get at least a CAT III, as you may run into situations in which you will have to do work at the meter or panel of the residence. 



Let's cut to the chase...


            A well-appointed, CAT III fork meter is useful in a broad range of environments (battery, small electronics, all residential work, service, agricultural, and light industrial). They are typically the easiest to manipulate and are safe and robust. For professionals who need to work with larger conductors, they may want to opt for a clamp meter, but for most new electricians the fork meter is the best possible option. 



What was your first T&M purchase?
Do you have any advice you’d like to share with a new electrician on the search?