Standards Through Time: Changing to Stay the Same

Reading time ( words)

The use of standards has, ultimately, propelled civilization forward. As the electronics manufacturing industry works to create, revise, update, and restructure standards, it helps to take a moment to review how standards, and the process of creating them, have occurred throughout history.

One dictionary defines a standard as:

• Something considered by an authority or by general consent as a basis of comparison; an approved model

• An object that is regarded as the usual or most common size or form of its kind

• A rule or principle that is used as a basis of judgment

• An average or normal requirement, quality, level, grade, etc.

Time Is the Beginning

Humans kept time by the Moon and the seasons for many millennia. The Egyptians are credited with developing the first solar calendar in about 3000 B.C. Coincidentally, at about the same time, the Mayan long-count calendar begins. However, it is unclear whether the long-count calendar starts with the first day of the calendar or the beginning of the world in Mayan mythology. Interestingly, Chinese legend suggests that Emperor Huangdi invented the Chinese solar calendar in 2637 B.C., which is also around the same time. Overall, humans began keeping solar calendars simultaneously on widely separated parts of the globe.

In general, solar calendars are based on precise astronomical observations and indicate the emergence both of mathematics, and of some form of record-keeping, whether written or otherwise. This is because a solar calendar fits almost, but not exactly, into the Earth’s rotational timing. The Earth's spin is slightly faster than the orbital rotation (known as the tropical year) so that a solar orbit completes in 365 days, 5 hours, 48 minutes, and 46 seconds. It's these fractional days that must be accounted for with leap days and other similar calendar adjustments.

Units of Measurement

Naturally, as humankind transitioned to agricultural societies, and trade routes were established, standards for measurement became important in wider and wider circles.

"The earliest recorded systems of weights and measures originate in the third or fourth millennium B.C. Even the very earliest civilizations needed measurement for purposes of agriculture, construction, and trade. Early standard units might only have applied to a single community or small region with every area developing its own standards for lengths, areas, volumes, and masses. Often, such systems were closely tied to one field of use so that volume measures used, such as for dry grains, were unrelated to those for liquids with neither bearing any particular relationship to units of length used for measuring cloth or land. With the development of manufacturing technologies, and the growing importance of trade between communities and ultimately across the Earth, standardized weights and measures became critical. Starting in the 18th century, modernized, simplified, and uniform systems of weights and measures were developed with the fundamental units defined by ever more precise methods in the science of metrology. The discovery and application of electricity was one factor motivating the development of standardized internationally applicable units."

This trend to have local "flavors" of units of measurement is a common theme throughout history. For example, the yard (the introduction of which is unclear) was localized throughout Britain until it was standardized sometime after 1100 A.D. to be the distance from King Henry I's nose to the end of his thumb (or so the story goes). Other sources (from the reign of Edward I or II, around 1300 A.D.) suggest that "three grains of barley dry and round do make an inch," and that all other measurements of length build up from this reference length. The imperial yard, however, goes on to play a key role in standards for length measurement.

In 1758, the legislature required the construction of a standard yard, which was made from the Royal Society’s standard and was deposited with the clerk of the House of Commons; it was divided into feet, including one of the feet into inches, and one of the inches into tenths. A copy of it, but with upright cheeks between which other measuring rods could be placed, was made for the Exchequer for commercial use.

In 1760, this standard yard was certified as the “imperial standard yard” from which all other imperial units of measurement then were derived. Of note is the exacting specification applied to the definition of this yard standard:

"…the straight line or distance between the centres of the two points in the gold studs of the straight brass rod now in the custody of the Clerk of the House of Commons whereon the words and figures ‘Standard Yard 1760’ are engraved shall be and the same is hereby declared to be the original and genuine standard of that measure of length or lineal extension called a yard; and that the same straight line or distance between the centres of the said two points in the said gold studs in the said brass rod—the brass being at the temperature of 62 degrees by Fahrenheit’s thermometer—shall be and is hereby denominated the imperial standard yard and shall be and is hereby declared to be the unit or only standard measure of extension, wherefrom or whereby all other measures of extension whatsoever, whether the same be lineal, superficial or solid, shall be derived, computed and ascertained…"

To read the full article, which appeared in the September 2019 issue of SMT007 Magazine, click here.



Suggested Items

IPC CFX Update v1.3

03/31/2021 | Michael Ford, Aegis Software Corp.
By the time that you read this, version 1.3 of the CFX standard should have been published. There are some very interesting additions in this release, including messages for predictive maintenance and smart energy management. As CFX is an IPC standard, the industry is assured of open content, designed to evolve Industry 4.0 manufacturing for everyone.

Real Time with… IPC APEX EXPO 2021: Developments in Digital Manufacturing

03/08/2021 | Real Time with...IPC
Michael Ford and Pete Starkey discuss the industry trend towards digital manufacturing, the latest in 3D CAD technology, ontological data and the benefits of the new IPC standard for digital twins.

BGA Standard Update With Ray Prasad

03/31/2020 | Real Time with...IPC
In this video interview from the show, Ray Prasad, president of Ray Prasad Consultancy Group, updates Guest Editor Joe Fjelstad on the ongoing work with the BGA standard and the latest revision that is going to ballot.

Copyright © 2021 I-Connect007. All rights reserved.