Measurements require precision, and precision requires proper calibration. However, when calibrating how do we know what a precise unit of measurement actually is? That’s all thanks to metrology.
In this article, we’ll discuss what metrology is, why it’s important, which sectors and industries rely on metrology, and more.
What Is Metrology?
Metrology is the science of measurement. It’s what establishes the standard measurements used not only in important scientific research but in every facet of life — from the food and products we buy to the medical tests and industrial standards we rely on to keep us safe and healthy. In all these areas and more, practitioners of metrology, i.e., metrologists, make sure measurements are standardized and reliable.
Despite its importance, metrology often goes overlooked. It may not be as headline-grabbing as the research it supports, but accurate measurements and standardized systems transcend languages and affect decisions made every day.
What Is Metrology Used for?
Metrology has a host of unique use cases. While the main use is for establishing standardized, reliable units of measurement, other common uses of metrology include the process of developing calibration standards against which to compare measurements and enforcing laws for those standards.
These uses are critical and span across different industries, too. Industries like aerospace and air transportation, food and beverage production and distribution, and telecommunication all rely heavily on metrology in order to carry out and maintain safe, high-quality products and services.
How Is Metrology Used in Manufacturing?
Another major use case for metrology that spans many varied industries is manufacturing. Nearly all of the items we depend on in our day-to-day lives—the transportation we use, the food we eat, even the medications we take to treat and prevent illness—are all manufactured by machines in a laboratory or factory.
In order to ensure manufacturing lines are functioning safely and properly, it’s critical for companies to have an accurate understanding of the performance of their machines. A machine that’s out of alignment can quickly become damaged and fail, costing a company both time and money to repair. Even more critically, an out-of-alignment machine can create unsafe working environments or faulty products that could jeopardize lives.
Metrology is crucial to controlling the quality of and maintaining the precision of machinery and manufactured parts. Regularly measuring different aspects of manufacturing machinery — such as the pressure a robotic arm is exerting or the temperature an automatic welding machine is reaching — helps ensure the equipment is operating at standardized, acceptable levels.
Metrology also helps ensure that equipment and the tools that measure its performance are calibrated for optimal precision and accuracy, ensuring conformity across machinery and correct measurements every time.
What Is an Example of Metrology?
The most famous example of metrology in action is the definition of one of the most common units of measurement used today — the kilogram.
The definition of what a kilogram actually is (i.e., the actual, precise weight of a kilogram) has changed many times throughout history. In 1799, French academics defined the kilogram as equivalent to the mass of a specific platinum artifact called the Kilogramme des Archives, or “Kilogram of the Archives”; it’s one of the earliest official reference standards. By 1889, 17 countries collectively agreed to adopt the International Prototype of the Kilogram (IPK) as an international reference standard. The IPK, another artifact made of metal (this time, a cylindrical alloy of platinum and iridium), was in use until quite recently.
However, physical objects degrade over time, even with proper care, causing historical fluctuations in the kilogram. So in 2019, experts agreed to change the reference standard of the kilogram from the IPK, a tangible object, to a universal constant of nature called Planck’s constant.
This evolution of the kilogram is just one example of the important role metrology plays in everyday life.
What Are the Types of Metrology?
Like nearly any scientific discipline, metrology is made up of many different branches and subfields. There are three main types or subfields of metrology:
● Scientific metrology
● Legal metrology
● Industrial metrology
Scientific metrology is the R&D of metrology, developing new units of measurement where necessary and establishing frameworks for international use. This subfield of metrology sets up the measurement systems and then declares them to the community at large. Some examples of the work that comes out of scientific metrology would be the definition kilogram and the development and maintenance of the metric system.
Legal metrology is the regulation arm of metrology. Instead of developing new measurement units, experts in legal metrology are interested in making sure the existing units of measurement are correctly measured and regulated in order to protect consumers and the economy. Work in this subfield contributes to the establishment of laws to maintain the transparency, traceability, and accuracy of measurements worldwide so that consumers and organizations can make decisions confidently and without issue.
Industrial metrology, or applied metrology, is the subfield of metrology centered around manufacturing, supply chain, and technology. It’s where findings and standards born out of scientific metrology are put into more practical use. Some examples of industries that rely on applied metrology include automobile manufacturing or pharmaceutical companies.
Types of Metrology Tools
The number of tools available to a metrologist is vast, but the usefulness of these tools depends on the situation and measurement needed. There’s no one-size-fits-all tool to get every job done. Here are some of the more common metrology tools.
● Manual precision measuring tools: These are tools that metrology professionals use, as the name suggests, to take measurements by hand. Gages, micrometers, and calipers fall in this category and, despite their analog nature, are still reliable for quick precision measurement.
● Coordinate measuring machines (CMMs): A vast improvement over manual methods, CMMs provide some of the most precise measurements available and do so quickly. They calculate exact distances and dimensions of an object by utilizing various probes and sensors (for example, laser and white light sensors) that can measure coordinates in three-dimensional space.
● Optical comparators: These tools measure the accuracy of 2D dimensions by using light and imaging sensors these sensors to compare the object being measured to its intended dimensions. Optical comparators are particularly useful for quality control checks in manufacturing to ensure that small parts are within tolerance.
● Laser scanners: These scanners operate by using a laser to collect measurement data in real-time. They’re especially helpful when the component being measured is sensitive to the touch.
Beyond Metrology
Clearly, metrology plays an essential role in making sense of the world around us and helping ensure the safety of products and services we use each day. The depth and breadth of all of the different ways of how measurements can be studied, defined, compared, regulated and collected only underscores the important role that calibration plays in metrology.
Without calibration, we risk relying on measurements and measurement tools that could be incorrect—a risk that can very quickly escalate to hazardous, even deadly situations.
To learn more about the importance of calibration, please read these resources:
Related resources
· Why is Calibration Important?
