MEASURE FOR MEASURE
Metrology considering the question of standardization
by Jay L. Bucher
What if all the calibration programs in the United States were not required to be traceable to the National Institute of Standards and Technology (NIST)?
The fact of the matter is there are no requirements, regulations or standards that call for traceable calibration to NIST or any other National Metrology Institute (NMI). Nor are there any requirements for other countries to be traceable to their NMIs.
In the spirit of ASQ being a global organization, I’ll list a few countries and their NMIs, all of which are signatories of the International Committee of Weights and Measures mutual recognition agreement:
- Germany—Physikalisch-Technische Bundesanstalt.
- United Kingdom of Great Britain and Northern Ireland—National Physical Laboratory.
- Japan—National Metrology Institute of Japan and the National Institute of Advanced Industrial Science and Technology.
- Republic of Korea—Korea Research Institute of Standards and Science.
- Australia—National Measurement Institute of Australia.
The bottom line of this "what if" statement is that most calibration traceability statements are incorrect. Their calibration records and calibration certificates should show traceability back to the International System of Units (SI), not to their NMI.
Back to the source
Standards and regulations are specific about all calibrations being traceable to national or international standards, also commonly referred to as the SI (remember, the SI used in the traceability statements are to one of the seven basic units or any of the derived units).
According to ISO/IEC Guide 99:2007, traceability is the property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty.1
The note at the end of the definition for metrological traceability defines "traceability to the SI" as "metrological traceability to a measurement unit of the International System of Units."2 The SI is based on the International System of Quantities.
Along with rules for its use, the SI was adopted by the General Conference on Weights and Measures, and interpreted for use in the United States. Test equipment calibration is not traceable to NIST, but rather to the SI. All calibration certificates and records should have a statement that declares their calibration is traceable to the SI.3
A follow-up to the initial question might be: What if all the calibration programs throughout the United States were to show their results recorded in their calibration records using the appropriate SI unit? Currently, that isn’t always happening. Major pharmaceutical companies are still using pounds instead of kilograms, pounds per square inch instead of Pascal and Fahrenheit instead of Celsius.
Part of the problem is their metrology departments either do not realize there is a requirement to use the SI, are under the misconception it would cost extra to convert to the SI or are being pressured by their facility services departments to continue using U.S. customary units because they are unwilling to convert to metric.
The simplest solution is to report the result in dual units by converting to the SI unit and still show the U.S. customary units in parentheses. Remember that most of these calibration records are for internal use only, and their data—when needed for labeling or shipping information—could easily use the SI, saving the shipping and purchasing departments the headache of converting from English to metric.
It’s important to note there are exceptions to every rule, regulation and standard. The same applies to use of the SI across different industries and applications. The point I’m is trying to make is that standardization of industry measurements—which units they report their results in—could be critical to the health, safety, economy and productivity of the customer, specific sectors and the public as a whole.
The U.S. NMI states the following in NIST Special Publication 811: "Note: The International System of Units … is the modern metric system of measurement. Long the dominant measurement system used in science, the SI is becoming the dominant measurement system used in international commerce."4
The Omnibus Trade and Competitiveness Act of August 1988 changed the name of the National Bureau of Standards (NBS) to NIST and gave the agency the added task of helping U.S. industries increase their competitiveness in the global marketplace. It also recognized the rapidly expanding use of the SI by amending the Metric Conversion Act of 1975.
In particular, section 5164 designates "the metric system of measurement as the preferred system of weights and measures for United States trade and commerce," and requires that "each federal agency, by a date certain and to the extent economically feasible by the end of fiscal year 1992, use the metric system of measurement in its procurements, grants and other business-related activities, except to the extent that such use is impractical or is likely to cause significant inefficiencies or loss of markets for United States firms."5
What if everyone started using the SI units as a matter of common sense and ease of use, and as a way to standardize measurements not only within our organizations and manufacturing industries, but also with all trading partners inside and outside the United States?
Made in China
On Jan. 21, 2005, during the annual Measurement Science Conference, the ASQ measurement quality division sponsored a seminar on metrology education. During that seminar, one of the audience participants was Klaus-Dieter Sommer from Germany.
Sommer explained he had been a guest professor at a university in China. He told how the university had an influx of 8,000 students every year, all of whom were studying measurement techniques within a metrology system.
He said the Chinese government increased attendance in metrology and measurement techniques to around 12,000 students. His question was, "Why doesn’t the United States and/or Germany train and educate in the field of metrology and calibration the way the Chinese are doing?"
The initial discussion centered on the lack of funding for higher education training or curriculum within either country. As the old saying goes, "The squeaky wheel gets the grease." Such is the case in America and Germany. Those crying the loudest or busy sticking their fingers in the leaky dike have the attention of politicians and grant-based organizations so much so that metrology falls to the wayside.
Don’t wait for trouble
Then, I had an epiphany. I raised my hand and answered, "Because we haven’t had the great train wreck yet." We haven’t had a disaster in which someone says, "Calibration was the problem." We haven’t had an event in which there was a great loss of life, many organizations went bankrupt, or many people lost their livelihood or retirement funds.
The automotive industry has had many train wrecks. Everyone remembers the problems Ford Motor Co. and Firestone had a several years ago. The airline industry has had many instances of tragedy and loss of life over the years, as has the nuclear industry.6
Wouldn’t it be great to be proactive in changing to the SI without sufferring the grief and pain of tragedy? Consider the industries that should be using one system instead of two or three: biotech, pharmaceutical, medical device and healthcare. The opportunities for catastrophic disaster in these industries are immense.
These fields cover areas such as drugs, cosmetics, implants, cancer research and genetic identity testing. Shouldn’t we consider taking the logical step and converting to the metric system in calibration or metrology departments in as many areas or measurements as economically possible?
Most of our working and reference standards already have the capability to read out in multiple units while providing conversions with the push of a button. What if we at least considered the options and alternatives? It’s 2013. Isn’t it about time we all moved into the 21st century?
- International Organization for Standardization, ISO/IEC Guide 99:2007—International vocabulary of metrology—Basic and general concepts and associated terms.
- Jay L. Bucher, "Out of Sync," Quality Progress, March 2010, p. 53.
- Ambler Thompson and Barry N. Taylor, The NIST Guide for the Use of the International System of Units, www.nist.gov/pml/pubs/sp811/index.cfm.
- "Omnibus Trade and Competitiveness Act of 1988," http://gsi.nist.gov/global/docs/omnibus.pdf.
- Jay L. Bucher, The Quality Calibration Handbook, ASQ Quality Press, 2007, p. 3.
Jay L. Bucher is president of Bucherview Metrology Services LLC in De Forest, WI. He earned a doctorate in traceable calibration technology from Almeda University. Bucher is the editor and coauthor of The Metrology Handbook, second edition, and seven other books, including A Calibration Training Program for the 21st Century. He is a senior member of ASQ, the secretary of the measurement quality division and a certified calibration technician.