Per Merriam-Webster’s online dictionary, metrology is “the science of weights and measures or of measurement.”  It can also refer to a system of weights and measures. 
Definitions are helpful, but application is more meaningful. Why are measurements so important? How does standardization work? What purpose does it serve in the real world applications of science, business, finance, and technology?
The Importance of Metrology
Metrology is important for several reasons:
- Knowledge must be shared.  Without common measures, an event cannot be described and documented so that independent, unbiased observers can reproduce that event.
- Measurements protect us.  From medication dosing to highway speed limits, numbers matter. Having a standardized number as a target, as well as having a standard measure for that target, protects the common well-being and potentially saves lives.
- Contracts and transactions must have numbers as a foundation.  Everything from food portions to gas pump prices is affected by many measures. Without numbers, acceptable (and unacceptable) performance cannot be described and determined.
- Measurements strengthen competition.  Once an industry knows both legal and customer requirements, they can analyze and determine how closely those are met. Then they can innovate and remain competitive by better meeting requirements.
Metrology in Operation
Obviously, having standard numbers is critical. But how is that achieved? How does society identify measures and implement them as standards?
First, it is critical to identify the what must be measured and the best measures to use.  Next, collaborate to generate approval for and acceptance of the measure.  Finally, codify how to use the measure  so others can use it.
Metrology in the Real World
Within metrology, there are three subfields:
- Legal: This subfield focuses on numbers used in legal or legislative efforts. The documented measures may protect personal health, improve public safety, increase environmental protection, or ensure fair trade on behalf of consumers. [3,4] The numbers in these efforts help develop and enforce fair rules for all.
- Applied or Industrial: People in this subfield concern themselves with numbers used to manufacture goods or to produce and refine natural materials. Once the numbers are established, people in this subfield also ensure proper calibration of instruments used to obtain numbers in the manufacture of goods or production of materials. [3,4]
- Scientific or Fundamental: Focus on scientific metrology allows the establishment of new units of measure and the development of methods for repeatedly obtaining measurements in the new unit. Those in this field gain community support for new measures and methods of measurement and teach general users how to use the measures and related methods. [3,4]
Throughout history, man has looked for ways to measure what he produces and its value. As early as 1875, a global need for standardized measurements was recognized.  However, the standards vary from industry to industry. The science of measurement and related standards continues to grow in need and popularity.
 https://www.merriam-webster.com/dictionary/metrology, last visited 12/21/2017
 http://www.french-metrology.com/en/history/interest-metrology.asp, last visited 12/21/2017
 https://en.wikipedia.org/wiki/Metrology, last visited 12/21/2017
 http://www.brighthubengineering.com/manufacturing-technology/63936-what-is-metrology/, last visited 12/21/2017
 http://worldmetrologyday.org/faq.html, last visited 12/27/2017
 https://digitalcollections.nypl.org/items/510d47db-bfd3-a3d9-e040-e00a18064a99, last visitied 12/27/2017