Using a clamp meter to troubleshoot a heating appliance

When working with a heating appliance, determining the cause of any problems is job one. One of the best tools to use for these tests is a clamp meter. It helps a tech discover and diagnose electrical problems that could be leading to other issues that the customer is seeing on their thermostat.

For a tech, it’s critical to have the right tools for testing and troubleshooting electronic controls. This ensures the safe and accurate measurement of parameters like amperage, capacitance, and voltage.

Picking up a clamp meter, like the Fieldpiece SC680 – 600 AC/DC Swivel Clamp Meter or a SC480 – 600A Clamp Meter helps a tech get to the bottom of what’s happening. Each clamp meter features a clamp jaw that’s designed to wrap securely around a wire. This helps the meter quickly and easily measure the amperage and frequency without the technician needing to touch the circuit directly.

These days, many new systems come with Variable Frequency Drives (VFDs). Their motors offer increased efficiency, but the noise they generate on the exiting voltage signal adds a level of complexity to diagnosing a system. The SC680 and SC480 each filter out the noise from the VFD and give the tech an accurate reading. Few other meters on the market do what these clamp meters do.

Not every diagnostic test runs using just the clamp meter though. Newer systems like mini-splits operate with high voltage signals and sometimes require thinner test leads to measure. The SC680 and SC480 measure up to 1000VDC and 750VAC and measure resistance into the megohm (MΩ) ranges. These higher resistance values are commonly seen on today’s more advanced systems. The SC680 and SC480 also come with needle tip test leads designed specifically for measuring Molex plugs on mini-splits.

When using a meter for the first time, use it to test known voltages – like a wall outlet or another known circuit on the job site. This helps the tech become acclimated with the device. In the outlet, the tech should find around 120 volts. But this may vary depending on the time of day, location, or during time of peak demand.

Another task for technicians is confirming proper operation of the flame sensor. The flame sensor generates a small current, measured in uADC. The SC680 and SC480 can also measure uADC, allowing the technician to diagnose and rectify on the spot.

When a tech is working on a transformer, both the primary and secondary side should be checked. There should be approximately 24 volts coming out of the secondary side. When the voltage on the primary side goes up, the secondary voltage should go up as well.

A continuity test shows a tech if a circuit is being completed in the system and helps them diagnose bigger issues like a broken wire in a motor. This test also shows if a switch is closed or open. It’s important to ensure all power is off to the circuit.

All of these tests can be quickly and safely performed using the Fieldpiece SC680 – 600 AC/DC Swivel Clamp Meter or the Fieldpiece SC480 – 600A Clamp Meter.


To learn more about these versatile clamp meters, visit


How to stay healthy and safe during heating season

Outside, leaves are changing and snow’s about to start coming down. This means service calls in inclement weather, working in cold, dark spaces, lugging heavy equipment up and down icy steps, and a host of other potential hazards. 


Here are a few ways to stay safe all season long: 


The first danger that a tech may encounter during the winter is cold. When working outdoors for extended periods of time, dress warmly from head-to-toe. Being tough is one thing, but it’s sure easier to get the job done with warm fingers and toes. Harsh exterior environments require warm, insulated boots, hats, and gloves. 


Another significant danger a tech might encounter is electrical. And the best way to deal with that is to treat every wire like it’s a live wire. Using a clamp meter, a tech is able to quickly test any exposed wires. Before attempting to perform any service or maintenance, make sure to turn off, label and lock breakers back at the circuit box to make sure nothing is accidentally turned back on while work is being performed. Note that units may have multiple power supplies. Working safe is the best way to work around electricity.  


In the world of HVAC, there’s a lot of heavy equipment. If something is too heavy for one tech to lift, find a co-worker to help. This minimizes potential injuries or damaged equipment. Also, before picking up something, learn about the best way to move it from place to place. And be aware of sharp edges and sensitive components. This minimizes personal injury and expensive equipment damage. 


While working in confined spaces, a tech could come across chemicals that could potentially harm them. These range from exhaust gases and leaking refrigerant to dust, mold and even asbestos. Carbon monoxide gas is a frequent danger too as it is odorless, colorless and potentially lethal. Techs should always wear the correct PPE when working around these chemicals and work to minimize exposure and follow the recommended ventilation requirements. 


To learn more about how to work better, faster, smarter and safer, visit 


Your Heating Season Must-Have Tool Checklist 

Another year of heating season is upon us, and HVACR pros know what that means. It’s time for a rush of service requests for inspecting and servicing furnaces and heat pumps. It also means you need to be fully equipped to work quickly, efficiently and safely during the harsh temperature drops and potentially risky situations the season presents. 

Is your truck and tool bag outfitted with the right tools to take on even the toughest jobs?  

These essentials deliver the confidence and safety you need to get the job done right: 


  • Combustion Analyzer. When you get to your first service call this heating season, you should be packing a combustion analyzer that is ready to detect and accurately measure gases like carbon monoxide, oxygen, carbon dioxide, draft pressures and more. Preferably, the combustion analyzer you use features real-time capabilities too, allowing you to troubleshoot while running combustion analysis and viewing trends, pressures and customer details all on one screen. And for those who are looking for even more bells and whistles, a combustion analyzer that automatically separates and returns accumulated water to the flue helps increase efficiency. 


  • Carbon Monoxide Detector. Your safety and the safety of your customers should always be top-of-mind when conducting service calls and repairs. Rely on a carbon monoxide detector that gives you and your customers peace of mind; ideally, you’ll find one with fast reaction time to enable quicker and safer testing, and an electrochemical sensor that is fast enough for a “walk-around” test, reacting to changes in CO levels in real time. 


  • Clamp Meter. Some service calls require you to troubleshoot an electrical system, and that is where a powerful wireless clamp meter comes in handy. While there are many clamp meters on the market, you want to use one that offers a bright display to help you work in any lighting; one that offers versatility and is packed with everything you need to install, service and troubleshoot any HVACR system; and hopefully, one that allows you to view electrical measurements from your mobile screen.  


  • Dual Port Manometer. You need a dual port manometer that has the ranges to measure gas pressure, is great for diagnosing furnace performance, and has the resolution needed to measure static pressure (down to 0.01″ WC). Fortunately, there are dual port manometers with pressure switch testers that find faulty pressure switches and help calibrate adjustable pressure switches. 


  • Psychrometer. Whether reading from a duct or register, techs need a reliable psychrometer that measures relative humidity accurately from anywhere on the system. To help enhance the way you work, you should opt for a psychrometer probe that handles extreme duct temperature as high as 250°F; has a flexible wand to enable easy placement anywhere on the system to help you avoid burns; and communicates seamlessly with your mobile phone with instant live readings.  


When conducting service calls and inspections and making repairs, play it safe by keeping essential heating season tools with you at all times. 


Did you know Fieldpiece offers a full portfolio of high-quality heating season tools? Check them out by visiting! 



Fieldpiece: How We Started, Where We Are.

Fieldpiece began in 1990 when the vision of a stick meter with detachable heads became a reality. The stick meter, which was tested, developed and refined over a three-year period, broke new ground in the industry and established Fieldpiece as an innovator helping HVACR pros work easier, faster and better.

Fieldpiece has come a long way since then by continuing to keep innovation at the forefront of its business and staying true to its roots of prioritizing the needs of the HVACR pro in the field. Today, with more than 30 years of experience creating best-in-class industry-leading tools, Fieldpiece continues to break the mold by delivering only the best HVACR tools technicians know they can rely on every day and on any job site. In fact, Fieldpiece lives by the` motto: “If we can’t make it better for the technician in the field, then we don’t do it.”

Continuing this tradition of innovation, Fieldpiece has made life better for HVACR pros including the recent launches of its latest generation of HVACR tools. From The more recent launches include various tool categories such as: vacuum pumps (VPX7, VP87 and VP67); leak detectors (DR58 and DR82); a vacuum gauge (MG44). In the last few months two new additions have made their debut – combustion analyzers(CAT85 and CAT45) and a wireless refrigerant scale (SR47) – the innovation never stops.

Fieldpiece engineers work closely with professionals in the field, allowing the brand to keep a pulse on the challenges techs face day-in and day-out. As a brand truly for HVACR pros, by HVACR pros, Fieldpiece has the patents to prove its commitment to innovation:

  • Rapid Rail® Sensor Technology provides accurate temperature readings in mere seconds, enabling high productivity. Plus, temperature readings are not affected by ambient air.
  • RunQuick® Oil Change System allows techs to change the oil on a vacuum pump without turning off the pump or losing vacuum. In less than 20 seconds, a tech can swap out the old oil for new oil with no mess.
  • SensorVault™ technology featured in the latest combustion analyzers (CAT85 and CAT45) prolongs sensor life to at least four years, guaranteed.
  • And the HydroCycle™ pump, only featured in the CAT85, automatically separates and returns water to the flue, so it’s one less step for a technician.

Want to learn more about Fieldpiece and the latest tools and technologies available? Visit www.fieldpiece.comtoday!















Make the most of your Wireless Refrigerant Scale SR47 

Here are a few ways that the Fieldpiece Wireless Refrigerant Scale SR47 is designed to make life better for HVACR techs in the field.  

Larger platform but still portable
As soon as you take it out of the carrying bag, you might notice its large 13-inch platform which is able to handle even larger tanks—we’re talking up to 252 pounds. The scale easily fits into its carrying case that slings over the shoulder meaning the highly portable SR47 is small enough to be carried anywhere while also handling even the biggest jobs. 

Tough as it looks
The new integrated rubber bumpers don’t just make it look pretty. Along with being able to handle larger tanks, the SR47 platform features an IP54 rating so it withstands jostling, splashes, dirt, dust and just about anything a tech comes across in the field. Set it where it needs to be set. The SR47 has you covered. 

The most accurate
The SR47 is more than just big and tough. It’s accurate. For a tech recharging a system, knowing exactly how much refrigerant is being added is critical to helping the system run at peak efficiency. This wireless scale offers industry-leading accuracy of: ±0.03% rdg + 0.25 oz. That means you’ll know exactly how much refrigerant charge you’re adding. Nothing on the market comes close to matching this. 

Wireless convenience
The SR47 isn’t a scale that needs to be babysat during a charge. It comes with a handy, back-lit IP64 rated remote that’s easy to read and stores inside the scale when not in use. The SR47 also works seamlessly with the Job Link® System App and the Fieldpiece SMAN Digital Manifolds, SM380V and SM480V. With an industry-leading 1000’ wireless range, a tech can keep an eye on the charge from anywhere on the jobsite while easily documenting and saving customer data. 

Week-long battery life
Most wireless tools have limitations in terms of battery-life, but the SR47 bucks that trend. The battery in the platform lasts for more than 200 hours.  

The Wireless Refrigerant Scale SR47 was designed to be easy for techs to use, tough enough for any jobsite, and smart enough to communicate with the Job Link® System App. That’s because it’s a Fieldpiece.   

Learn more about the Wireless Refrigerant Scale SR47 and all Fieldpiece products. 


Press Releases


New Refrigerant Scale Breaks the Mold with Expanded Durability, Accuracy and Portability to Support HVACR Field Professionals 

ORANGE, CALIF., SEPTEMBER 01, 2022Fieldpiece Instruments today announced the launch of an upgraded Wireless Refrigerant Scale, model SR47, for HVACR contractors and technicians. The latest model will replace the industry workhorse, Fieldpiece’s SRS3. The newly upgraded wireless refrigerant scale is yet another gamechanger to make HVACR industry tools more efficient and effective with the ultimate performance and durability in a compact, portable design. Industry-leading battery life, wireless range and accuracy offer unmatched reliability and convenience. 

HVACR industry technicians rely on refrigerant scales for AC system installation and maintenance to accurately measure the weight of refrigerant – critical for the refrigeration industry. Scale accuracy is especially important when considering that no two system refrigerant requirements are the same.  The new Fieldpiece Wireless Refrigerant Scale, SR47 is designed to meet those needs, and is ideal for residential or commercial HVACR technicians that need to charge and recover refrigerant quickly and move on to the next job. 

“We designed a wireless refrigerant scale that we knew the industry needed most for the best accuracy, durability and portability,” said Jeb Ball, Vice President of Sales and Marketing at Fieldpiece Instruments. “As an HVACR industry leader, we are proud to provide the most rugged and dependable tools offering the best possible range in the field.”  

The SR47’s 252-pound maximum load capacity accommodates any charge or recovery requirement, while its oversized 13-inch platform design with unique integrated bumpers is engineered to fit any refrigerant tank. It also features the best platform battery life in the industry with a long life of up to 200 hours, which maximize jobsite uptime by removing the need to change or recharge batteries. 

The SR47 offers industry-leading wireless 1000-foot range with the Job Link® System App, allowing technicians to easily capture data and send reports or invoices, and it integrates with other tool measurements such as SMAN digital manifolds. Its wireless remote can be easily stored in a handy niche located under the scale and it boasts an improved rubber gasket grip design, shorter length, slightly larger display and a redesigned magnet, plus a hefty 80-hour battery life. 


Technicians need tools that are lightweight yet durable enough to withstand wear and tear in field conditions. The Wireless Refrigerant Scale, SR47 meets both requirements. Its compact size and lightweight seven-pound portability make it easy to carry up a ladder while its rubberized corners offer robust impact protection. Wet weather is no barrier to performance – the SR47 is weather resistant with an IP64 rating for the remote and an IP54 rating for the platform so techs can work in the rain if they need to. 

This new “heavyweight champion” from Fieldpiece also comes with a protective case that’s easy to carry over the shoulder between jobs from residential sites to commercial rooftop units and includes protective padding to withstand truck or van transport and storage. A raised power button at the base of the scale improves usability and ergonomic design. As with any Fieldpiece tool, technicians can take advantage of the exceptional Fieldpiece live technical product support for one-on-one product guidance. 

For more information, visit: 

ABOUT FIELDPIECE: Fieldpiece Instruments is an innovative technology company focused on helping industry professionals do their jobs easier, faster and better. It delivers on this promise through industry-leading devices and a broad range of professional-grade tools and technology inspired by real-world application and field use. Fieldpiece is focused on serving the HVACR industry exclusively, enabling HVACR professionals to become masters of the trade. Discover more at, and follow Fieldpiece on Facebook, Instagram, YouTube and LinkedIn 

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