World Metrology Day: Why The Science of Measurement Is Something to Celebrate

Even though it touches virtually all of the objects in our lives — from the cars we drive to the prescriptions we take — the field of metrology remains a mystery to most people. But every year on May 20, this vital science steps into the spotlight as we celebrate World Metrology Day.

Celebrating the Science of Measurement
Organized jointly by the International Bureau of Weights and Measures (BIPM) and the International Organization of Legal Metrology (OIML), this global day of recognition raises awareness of the importance of metrology — the science of measurement — in our daily lives. The annual event also celebrates the contributions of those who work behind-the-scenes in metrology labs and organizations around the world.

“Measurements for all times, for all people” is the theme of World Metrology Day 2025. This theme underscores how accurate, traceable measurements contribute to progress in every generation — from scientific and technological innovations to addressing global challenges like public health and climate change.

150 Years of Global Collaboration
May 20 was chosen for World Metrology Day to coincide with the anniversary of the Metre Convention held on May 20, 1875. This historic event brought together 17 nations to create the International Bureau of Weights and Measures and establish a global framework for universal measurement standards. The convention ushered in a new era of international cooperation and uniformity in metrology.

As a means to ensure fair trade, the Metre Convention participants agreed upon the use of the metric system to measure weight and length. Their mission for uniform measurement remains relevant 150 years later, though the original participants might be surprised at the massive and miniscule things metrologists measure today — and the accuracies with which we measure them.

Early Metrology
The etymology of the word “metrology” derives from the Greek “metron” plus “logy,” which literally translates as the “study of measurement.”

One of the oldest systems of weights and measurements, metrology was originally established using the human body as a scale. This is where we get the terms “foot” and “cubit”. This was an inaccurate scale of measurement because foot size and limb length vary greatly among people. Regardless, these measurements were used for thousands of years to build structures and make trades — with far less precision than we are accustomed to today.

For example, back in 1628, these variable and unreliable measurement standards led to the sinking of Sweden’s large Vasa warship, just minutes after it went to sea. The catastrophe claimed the lives of all 30 people on board. When the ship was recovered more than 300 years later, researchers discovered that the roughly 12-inch ‘Swedish foot’ was used to construct one side of the ship, while the approximately 11-inch ‘Amsterdam foot,’ was used to build the other side. This made one side of the ship heavier than the other, making the ship vulnerable to an unseen enemy: the wind.

Clearly, a lot can go wrong when consistent, accurate measurements are not used — from the precarious position of the Tower of Pisa to the loss of NASA’s Mars Climate Orbiter in 1999.

Fortunately, today’s modern technology has made metrology far more refined and advanced. We now have standards of measurement that define exactly what a foot and a meter is. We also have far more accurate methods for measuring items compared to the standard units.

Metrology in Manufacturing
There is no room for error when it comes to the safety and quality of manufactured products. Metrology plays a crucial role in creating functional products that fill our lives. Without the use of metrology in manufacturing, large assemblies such as automobiles or airplanes would likely never assemble reliably and medical devices may not perform as intended.

Metrology in manufacturing is the study of how to reliably measure and manufacture a product. (The process is also referred to as quality inspection, dimensional inspection, validation, verification, product evaluation, contract inspection, and layout inspection).

Anything that has undergone a manufacturing process has been impacted by the science of metrology — measured or inspected in some form or fashion. Metrology labs use coordinate measuring machines (CMMs) and other equipment to capture the geometric dimensions of manufactured parts to ensure they meet design specifications.

From the earliest design stages to first article inspection, metrology provides reliable product measurements that help manufacturers improve quality, safety and dependability. Metrology also helps companies ensure that they are complying with all applicable specifications, standards and regulations.

Mastering Modern Metrology
As one of North America’s most trusted providers of laboratory services, Industrial Inspection & Analysis (IIA) is proud to provide metrology services and expertise to our nation’s military and many highly regulated industries, including aerospace, medical, food and beverage, and more.

Our ISO 17025 accredited metrology labs provide dimensional and GD&T inspection, advanced 3D scanning, modeling, analysis, and geometry re-creation in every phase of product design and production. Our toolkit includes state-of-the-art blue and red-light laser scanners, computed tomography (CT) scanners, touch probe and optical CMMs, profilometers, and more.

IIA’s highly skilled professionals use proven testing techniques that translate seamlessly from conventional manufacturing to 3D printing, precision manufacturing, and Industry 4.0. Whether a part or product is manufactured with standard metals, exotic alloys, biomaterials or plastics, IIA delivers data you can depend on.

Celebrating Metrology Every Day
Precise, reliable measurements are vital to every aspect of human life. By helping to advance realms ranging from science and medicine to technology and engineering, metrology has helped make our modern world what it is today.

With metrology labs across the U.S., IIA is proud to be part of a field that contributes to quality of life around the world. On World Metrology Day — and every day — we salute the professionals and standard keepers who are the unsung heroes of metrology.