How We Calibrate Faro and Romer Portable Arms

Published by CMMXYZ on June 2, 2021

Calibration is an essential component of maintaining the accuracy of a coordinate measuring machine. Without it, there is a greater risk of inaccuracy and equipment failure. Portable CMMs are often subjected to more extensive usage than traditional CMMs, requiring more frequent maintenance.

At CMMXYZ, we offer professional metrology services across North America, including Faro and Romer portable arm calibrations. For more than 30 years, our licensed team of CMM experts has delivered industry-leading calibration services designed to reduce equipment inaccuracies and increase quality control.

We’re proud to be the industry’s leading metrologists, offering a spectrum of services, including on or off-site measurements, certified training, system upgrades, and equipment repairs. We specialize in calibrating portable arms to ISO standards, ensuring each piece of equipment is operating at its highest level of accuracy.

What is a Portable Arm? 

Unlike traditional coordinate measuring machines, a portable CMM can be relocated from facility to facility. A portable measuring arm can take three-dimensional measurements of various unique surfaces and may be used for specific applications, including rapid prototyping and reverse engineering.

CMMXYZ offers calibration services for all makes of portable arms, specializing in Romer and Faro arms.

Romer Portable Arms 

Romer arms are a valuable piece of measuring equipment and are known as one of the most versatile tools in the industry. This portable arm is an inexpensive and accurate solution to complex objects that require precise 3D scanning. Romer arms, including the Romer absolute arm, offer efficient assembly and disassembly combined with a lightweight carbon fibre composition, allowing easy transportation between facilities.

At CMMXYZ, we can supply Romer arms with an integrated software system that allows for precise inspection on the shop floor using a kinematic probe. Combined with our software, a Romer arm can measure complex surfaces, reverse engineer, and secure thousands of data points per second. Romer models are ideal for sheet metal, elaborate die work, and moulded components with plastic injection.

How Do Romer Arms Work? 

Romer portable arms are used to carry out industrial measuring tasks when the surface that must be measured is too heavy or complex to move. The arm measures in 3D space with six or seven joints, which means a Romer arm can move forward and backward, up or down, and left or right, combined with an approximate rotation of three perpendicular axes. Each movement along the three axes is independent of one another.

How Do You Calibrate a Romer Arm? 

Calibration of a Romer arm involves a series of tests used to determine the accuracy of the arm’s angles, point positions, and the functionality of the probe. Through Romer's software, data is collected after each measuring test which our trained metrologists compare to the current ISO standards.

How Accurate is a Romer Arm?  

Romer arms are known across industries as one of the most accurate measuring models on the market. Their lightweight structure and flexible movements are indispensable, particularly for objects that cannot be transferred to a shop floor machine. Romer arms feature encoders in their primary axes, so the arm understands the position of its joints. This ensures accuracy every time.

Faro Portable Arms 

A Faro portable arm is a versatile measuring machine that offers various system integrations, allowing the operator to customize this CMM per their specifications. This CMM collects and compares data to blueprints or drawings for more dimensional analysis.

Just like Romer models, Faro arms can migrate from department to department with simple assembly and disassembly. Its ergonomic design reduces user efforts and overall fatigue. These metrology machines offer real-time feedback and reverse engineering analysis, elevating the performance and measuring standards of portable CMM machines.

How Do Faro Arms Work? 

Faro arms are equipped with multi-axis configurations (6 and 7 axis). Its high-resolution scanning abilities allow for rapidly scanning surfaces using its Laser Line Probe. A Faro arm uses contact measurement, which is connected to kinematic probes. This helps shop floors and manufacturers improve their products, lower operating costs, and accurately measure any geometric object.

How Do You Calibrate a Faro Arm? 

Calibrating a Faro arm involves carrying out a series of tests as designated by the appropriate calibration standard. Our trained metrologists will assess the functionality and accuracy of the arm and the probe using the data collected and compare the results to the current ISO standards.

How Accurate is a Faro Arm?   

Faro arms are known for their versatility and accuracy due to their multi-axis rotations, allowing the machine to move through various locations. Their ability to measure on-demand without a precisely programmed routine is a sought-after feature that delivers reliable, consistent measuring results.

What is Calibration? 

Calibration is the comparison of the device’s accuracy to an artifact of known precision. This artifact must be traceable to a national standard and be certified.

Why is Calibration Important? 

Portable CMMs are often transported between facilities and on various modes of transportation throughout the year. Because of this extensive travelling, there is a greater chance of wear-and-tear, which can cause the machine to provide inaccurate data. Regular calibration is an essential step that technicians must take to ensure each piece of measurement data is correct and within the tolerance of the part being measured.

Calibration is an essential component of maintaining your portable arm’s quality standards. Here at CMMXYZ, we are primarily a Romer portable arm service center for tactile and scanning arms. We also can calibrate all brands of portable/articulating arms (both Faro and Romer included). Our fully certified ISO/IEC 17025 accredited lab delivers a guarantee of conformance to national standards.

The Steps of Portable Arm Calibration

To ensure accuracy and safety, portable arms must be calibrated at least once a year. To successfully calibrate a Romer or Faro machine, there are three steps involved in the procedure. Each step must follow industry standards to remain effective. Our calibration services ensure Faro and Romer arm best practices are continuously followed.

Single-Point Accuracy Test 

A single-point test is designed to assess the ability of the portable arm using a trihedral seat or precision reference ball positioned at three separate locations on the object.

Volumetric Ball Bar Test 

This performance test measures the aspects of linear movement and the accuracy and kinematic performance of the Romer or Faro machine.

Effective Diameter Performance Test 

The precision of the reference ball and temperature at the time of testing are critical factors in the success of the final test.

Benefits of Calibrating Your Faro or Romer Arm 

Regular calibration is essential to the integrity and longevity of a portable coordinate measuring machine. Without proper calibration, operators risk incorrect measurements and software errors. The yearly calibration yields significant benefits to CMM operators.


Calibrating a portable CMM ensures each data point is collected and stored with optimal accuracy. Due to the mechanical complexity of a portable arm, frequent testing of the arm to a known artifact and annual calibration is essential.

Tailored Processes 

Calibration services are tailored to meet the requirements of Romer and Faro portable arms. Every portable arm requires a thorough calibration process tailored to the machine’s structure and capabilities.

Industry Standards 

Calibration processes are executed to ISO standards. The Independent Organization for Standardization ensures the safety and quality of all CMMs. Regular calibration is essential to ensure your portable arm is operating securely and without error.

How Often Should I Have My Romer or Faro Arm Calibrated? 

Regular calibration is essential to ensure data accuracy and to optimize performance. Portable CMMs are often transported from one factory floor to another and may endure significant wear and tear.

At a minimum, it is wise to have your portable arm calibrated once annually. In cases where you're involved in high-tolerance work, such as the aerospace or automotive industry, your portable CMM is likely operating for extended periods and being transported regularly from plant to plant. More frequent calibration is recommended, approximately every six months, to ensure its accuracy and optimal performance.

It is essential to understand that a portable arm needs more scrutiny than a coordinate measuring machine. A coordinate measuring machine stays in one spot while a portable arm, by nature portable, is moved throughout a factory. It's assembled, disassembled, put on fixtures and put on surface plates. Generally speaking, it receives a lot more abuse than a coordinate measuring machine because it's used manually.

At CMMXYZ, we operate in a state-of-the-art ISO 17025 accredited Lab. Each step of our calibration process is aligned with the current standard for calibration (ASME B89.4.22-2004 R2019). We provide ISO 17025 calibration services for all makes of portable arms, including Romer and Faro models.

As leading metrologists in North America, we operate under ISO 17025 accreditation along with ISO 9001 certification and as a Hexagon certified Romer arm calibration centre.

What to Look for in a Romer & Faro Arm Calibration Specialist 

Choosing a CMM specialist to calibrate your portable arm isn’t a task to be taken lightly. CMMs are meticulous machines with several axis points, which require regular calibration from licensed professionals. To ensure your portable Faro or Romer arm is carefully inspected and calibrated accurately, you must select a specialist with the necessary qualifications.


Proper certification is essential in a CMM provider. Each component of a portable arm must be meticulously calibrated to meet industry standards. Our trained metrologists have ISO accreditations to ensure each step of the calibration process is as safe and accurate as the equipment itself. Our accreditations allow our certified instructors to offer industry-leading CMM training services to help advance aspiring metrology careers.

ANAB & ISO Certification 

The ANAB is the national accreditation body in North America. To obtain ISO/IEC 17025 accreditation and ISO 9000 registration, companies must be assessed by the ANAB through an independent assessment of its components, equipment, and staff. At CMMXYZ, we test Faro and Romer arms according to the standards set by ISO/IEC 17025.

Efficient Turnaround 

Specialists need to have the ability to offer calibration services in an accelerated time frame. Your shop floor is full of complex surfaces that require a functioning portable arm to collect data accurately, which means bringing it in for repairs and calibration cannot take up a significant amount of time. Our metrologists are trained to provide fast calibration services and measuring solutions without sacrificing quality control. This puts your CMM back on the factory floor before you even realize it’s gone.

Open Communication 

A qualified CMM provider will prioritize communication at every step of the process. When it comes to scheduling your calibration appointment, we’ll notify you 60 days before your certificate’s expiry date so that you can schedule an appointment at your convenience. From the moment your portable arm reaches our accredited lab to the minute it leaves our facility, we will provide continuous updates on its progress and confirm the date of the final calibration.

Working with CMMXYZ 

We’re proud to be North America’s premier CMM solutions provider, specializing in portable arm maintenance and calibration. Our team of licensed metrologists provides safe and efficient calibration services to ensure each CMM operates at optimal accuracy.

At CMMXYZ, we know how vital quality calibration is to the performance and longevity of portable new and used CMMs like Faro and Romer arms. We provide hassle-free services in our ISO accredited lab with a guaranteed quick turnaround.

Our professional metrologists are available to answer any of your calibration questions and explain our services. Contact CMMXYZ today to get started.

Request your portable arm calibration quote here

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