Metrology can be defined simply as the science of measurement, but it’s rarely that simple in practice. Measurements touch nearly every part of life, and that means metrology does as well. However, as a field, metrology is not a pillar. It’s made up of both larger subfields and more niche branches, and to better understand the work metrologists do every day, it’s important to know the differences between these types of metrology.
Introduction to Metrology
According to The International Bureau of Weights and Measures, metrology is the science of measurement and the application of that measurement. Metrology covers everything from creating new standardized international measuring systems to regulating and enforcing laws that protect fair trade.
Due to the breadth and importance of metrology’s different functions, there are naturally distinct types of metrology that each have a unique focus.
What Are the Types of Metrology?
There are three major subfields of metrology:
- Scientific
- Industrial
- Legal
These subfields make up the majority of the overall field metrology, with smaller offshoots existing within them.
Scientific Metrology
All metrology starts here. Scientific metrology is the subfield in which metrologists research measurements and create new standards, i.e., the references against which all other measurements are compared.
The main purpose of scientific metrology is to establish units of measurement. Researchers in this subfield produce findings that ultimately determine, for example, how much a kilogram weighs or how long a meter is. Scientific metrology is also vital in developing measurement standards for widespread adoption. Whenever a new technology or branch of scientific study crops up, it requires its own standards to ensure future work adheres to and utilizes the same numerical information in calculations and statistical analysis.
However, scientific metrologists also utilize cutting-edge science to provide new tools and frameworks wherever needed. For example, the U.S.’s National Institute of Standards and Technology (NIST) is utilizing quantum sciences to make smaller, more affordable measurement tools and systems.
That said, there are a few smaller branches of scientific metrology. The most common branches include:
- Electrical metrology: Standardizes voltage and resistance based on fundamental physical constants.
- Temperature metrology: Standardizes temperature measurements at large while also standardizing the temperature used in dimensional measurement to 20 °C.
Industrial Metrology
Industrial metrology is where scientific metrology is put into action. Industrial metrologists use the standards that scientific metrologists set in real-world applications. This subfield of metrology is crucial in the world of manufacturing, since the work that industrial metrologists do ensures product conformity, quality control, and the precision of manufacturing machinery.
A significant aspect of industrial metrological work is guaranteeing that all relevant parts of industrial machinery are within acceptable tolerances and are properly calibrated. Calibration itself is often the first step in industrial metrology, establishing a connection between the standardized units of measurement and the resulting output of a machine. Without proper calibration, machines can work inaccurately or wildly outside acceptable precision. This can create unsafe working environments and products, leading to a loss of time, money and even lives.
The ultimate goal of industrial metrology is to create a reliable and correct result every time. Whether that means the mass production of an identical product or a replicable accurate measurement, metrology touches all parts of the manufacturing pipeline.
Dimensional Metrology
Dimensional metrology is a more specific but prevalent form of industrial metrology solely focused on measuring the physical qualities of an object. Metrologists in this branch measure the dimensions of an object or the distance from it. Similar to industrial metrology, the goal of dimensional metrology is often to ensure that something is accurate compared to an original blueprint.
Legal Metrology
Where scientific metrology exists to create new standards, legal metrology is the subfield that makes those standards stick. Legal metrology exists to regulate and codify the standards of measurement as law. Professionals in this subfield focus on protecting consumers by writing and enforcing laws to ensure all measurements are transparent and traceable.
They also help protect fair trade by determining the legal requirements for measurements and ensuring that companies don’t report fraudulent measurements in order to deceive or sway the public. Legal metrologists also perform quality assurance, inspecting instruments and confirming the validity of any machines used.
Laboratory Metrology
Laboratory metrology is a hands-on form of legal metrology. It ensures the traceability and validity of reference standards and trains others in metrology methods as needed.
The Role of Metrology in Industry 4.0
The above overview provides a good sense of where metrology stands today, but the world of metrology is rapidly changing. We’re in the midst of Industry 4.0 — a term that refers to the rapid technological advancements happening in the 21st Century. For instance, technologies like artificial intelligence and machine learning continue to advance the ongoing digitization of manufacturing as companies strive for an entirely automated manufacturing process.
As technology progresses, metrology does as well. Now, the Internet of Things (IoT) and cloud computing allow experts to take, store, and access real-time measurements. Advancements in sensors have allowed for non-contact measurements, with scanners now able to measure both the internal and external dimensions of an object at once.
As these processes become automated, manufacturing and metrology it will become easier and more efficient, underscoring the importance of proper calibration.
