NIST 260-150

Standard Reference Materials - The First Century

Stanley D. Rasberry, Author Tomara Arrington, Composition and Design

Standard Reference Materials Program

Technology Services National Institute of Standards and Technology

Gaithersburg, MD 20899-2320

January 2003

U.S. Department of Commerce

Donald L. Evans, Secretary Technology Administration

Phillip J. Bond, Under Secretary of Commerce for Technology

National Institute of Standards and Technology Arden L. Bement, Jr., Director

Please visit our website WWW.ni st.gov/srm
Foreword

standard Reference Materials have played a major role in the history of the National Institute of Standards and Technology (NIST), as well as its predecessor organization, the National Bureau of Standards (NBS). Standard Reference Materials (SRMs) were one of the first tangible outputs from

the nation's investment in improved measurement standards and technology that was started at the beginning of the 20th century. As both NBS/NIST evolved over the last hundred years in terms

of scientific capability and fields of work, SRMs have taken on new forms and new roles in ensuring that our Nation is second to none in measurement capability. No one is more familiar with the history of this important program than Stanley Rasberry, long- time Chief of the program as well as a major developer of SRMs himself. In this retrospective, Rasberry captures the spirit and importance of the program for analysts, researchers and technologists everywhere. The reader will find this lively exposition both informative and enlightening about one of NIST's most important programs. John Rumble

January 2003

Acknowledgment

The Author wishes to acknowledge the fine contributions of Nancy Trahey-Bale and Lee Best for

their assistance in preparing this document.
standard Reference Maten^is i ne First Century
The entire charge to the new agency was

found in six provisions:

• custody of the standards;

• comparison of the standards used in scientific investigations, engineering, manufacturing, commerce, and educational insti- tutions with the standards adopted by or recognized by the Government;

• construction, when necessary, of standards, their multiples and subdivisions;

• testing and calibration of standard measuring apparatus;

• solution of problems which arise in connection with standards; and,

• determination of physical constants and

the properties of materials, when such data are of great importance and are not

to be obtained of sufficient accuracy else- where. The Bureau could have emerged at no more

opportune time. It was the dawn of virtually every technology that we know today - automobiles, airplanes, modern ships and locomotives, steel construction, motion pictures,

practical radio, and subsequently, television, space craft, computers, and information tech- nology. In the early days, the Bureau was

"right in the middle" of every one of these

fields. As we shall see, analytical chemistry had a role in most. The need to be relevant frequently directed the early work in analytical chemistry to topics where materials simply were not up to the challenging new applications. With these enormous needs in mind,

the Congress of the United States gave careful deliberation to the staffing of the new

Bureau. Initially, it decided it would not be

sufficient to have a director, a physicist and two assistant physicists; a chemist and two

assistant chemists also would be allocated.

Later, in 1901, the expense of constructing the new laboratory and the scarcity of funds caused the Congress to cancel the two assis- tant chemist positions. Thus in its first year, the young agency began trade-offs between

staff and facilities that last to this day. An Urgent Need

Many of the greatest technical challenges of the early twentieth century were related to materials and their performance.

Construction of skyscrapers and suspension

bridges would require new and stronger

alloys of steel, and better quality control for Portland cement used in concrete. Tungsten

alloy performance would become critical to vacuum tubes for lighting and electronics. Copper alloys would figure heavily in wiring

for communications and in valves and fittings with nearly endless configurations.

Perhaps the material concerns were nowhere more critical than in the automotive fields. Practical automobiles and aircraft were on

the threshold - they needed an

array of new materials ranging

2 Standard Reference Materials - The First Century
from nodular cast irons to high strength aluminum alloys to specialized rubber to carefully tempered glass. New and vastly larger

ships were on the drawing boards - they needed new alloys of corrosion resistant

steel, monel, bronze, and many other improved materials.

could help |- . with ques- - " . • .

• ^ - tions of laboratory ' -^"^

internal consistency but shed little lighfon

analytical disagreements among several laboratories. Methods were practically limited to those based immediately on first principles where standards could be physical. This still left open questions of completeness of separation, stoichiometry, purity of reagents, and

other issues. Evaluating the accuracy of newly

emerging instrumental methods would pro- duce even greater need for certified reference

materials to serve, first as accuracy benchmarks, and then as calibrators for quality assur- ance into the future. The Bureau accepted the challenge and set to work - but not alone. In fact, this very first reference material project set a precedent for cooperative efforts that continue to this day. Included in that precedent is the idea that

projects will be started only on demonstrated need and demand of the technical community. Furthermore, priority will be assigned to those projects where cooperation of the

requesters is assured. This has helped the Bureau select worthy projects over the years. The cooperation has included provision or preparation of materials and contribution of data to the certification campaign. In the

case of the first ever project, cooperation

with the American Foundrymen's Association extended to all three of these aspects. The

Railroad trains had already increased the speed of overland transport by an order of magnitude, but not without the cost of many

lives due to material failures. The first pas- senger fatality had occurred in 1833, near Heightstown, NJ. Former president John

Quincy Adams and Cornelius Vanderbilt were

aboard the train, but not injured. Preventing

future loss of lives was an urgent need that

pressed the Bureau into the new venture of

certifying reference materials.

In 1905, the American Foundrymen's

Association approached the Bureau to see if

it would assume leadership of a new work

the Association had recently begun. The

Association was trying to solve the problem

of rail car derailments due to the fracturing of cast iron wheels. Appropriate alloys had been found and Association research showed

that they would cure the problem. However,

the chemical laboratories at the various foundries that supplied materials to the rail- roads could not analyze the materials with

sufficiently consistent accuracy to provide ongoing quality assurance. The problem as the foundrymen defined it was to have a source of accurately analyzed materials having compositions at and bracketing the compositions of alloys known to be acceptable. Those "standardizing" materials could then be used by the foundries to maintain their analyses in control. At the time, chemists throughout the world were expected to develop and maintain their own lots of materials that could be used as benchmarks for calibrating or testing analyses.

Standard Reference Materials - The First Century 3
When the first project was completed in 1906, four materials were placed on sale together with their certificates of analyses to

serve as the needed benchmarks. They consisted of bottles of cast iron chips which were

labeled "Standardizing Iron Sample A," through "Standardizing Iron Sample D." Their worth was quickly realized in improved

cast iron rail car wheels and an improved

safety record for the railroads.

analytical work was carried out in several companies that were members of the

Association, and the Association provided to the Bureau an industrial research associate to do the analytical work at NBS. The young

chemist, John Cain, would become a full member of the staff, about twenty years

later.

certification campaigns were required to pro- vide new certificates of analysis. Also differ- ent was the labeling system. By the time the second lots were prepared, the cast irons were part of a larger program of reference

materials, which by about 1910, had become known as "Standard Samples."

"Standardizing Iron Sample B" became

"Standard Sample No. 4a - Iron B." The numbers 3, 4, 5, and 6 were never assigned with- out the "a" designation, owing perhaps to the originals having been issued with letter designations. Standard sample numbers 1 and 2 had been assigned to other materials, so they were not available to the cast irons. Two of the original formulations of cast iron have been renewed at every exhaustion

since. For Cast Iron C, there have now been

14 lots prepared over the past 95 years. When the initial lots of materials were

exhausted, they were replaced with new lots of nearly equal composition. Of course the new lots were slightly different, thus new

Success inspires imitation

The success of the cast iron reference materials led to expansion of the concept into new

material types. Certification work on several other alloys, iron standard Reference Material (SRM) 5m is ttie fourteenth lot (thirteenth renewal) of

Standardized Iron Sample C, and has in recent years, been certified in cooperation

with ASTM. Note the "C" designation has been dropped.

ores, and copper

slags began the same year as the

cast irons were

issued. All these

activities caught

the interest of the

steel producers. A

member of the

Bureau's Visiting Committee, Albert Ladd Colby, was a leading authority on metallurgy, and

he urged the Bureau to extend

its success with cast iron into the field of steel. Perhaps because it was

smaller then, the Bureau was quite

4 Standard Reference Materials - The First Century
agile in starting new projects and new cooperative ventures. It was able to start this new

effort together with the Association of American Steel Manufacturers in 1907. A

series of 17 steel standard samples emerged

and set NBS-NIST on a path of support to the

U.S. steel industry that has spanned nine

chemical analysis. More importantly, the

interest of the Nation's chemists was growing

too, with observation of the utility of the "Standard Samples" wherever they were

available. Clearly, more types of materials would be needed, and they were on the way

with the cooperation of the American Chemical

Society, and

sk^ later the Portland

Cement

Association, the Copper

Table 1. The First 14 Metal Reference Materials and their First Renewals (with numbers)

Standardized Iron Sample A 1906 Standardized Steel Bessemer 0.4 1907

ss 3 White Iron 1958 SS 10a Bessemer Steel 0.4 % C 1911 Standardized Iron Sample B 1906 Standardized Steel B.O.H. 0.2 1908

ss 4a Cast Iron B 1910 SS 11a Basic Open Hearth Steel 0.2 % C 1911 Standardized Iron Sample C 1906 Standardized Steel B.O.H. 0.4 1908

ss 5a Cast Iron C 1910 SS 12a Basic Open Hearth Steel 0.4 % C 1911 Standardized Iron Sample D 1906 Standardized Steel B.O.H. 0.6 1908

ss 6a Cast Iron D 1910 SS 13a Basic Open Hearth Steel 0.6 % C 1911

ss 7 Iron E 1917 Standardized Steel B.O.H. 0.8 1908

ss 7b Cast Iron (High Phosphorus) 1926 SS 14a Basic Open Hearth Steel 0.8 % C 1911

Standardized Steel Bessemer 0.1 1907 Standardized Steel B.O.H. 0.1 1908

ss 8a Bessemer Steel 0.1 % C 1911 SS 15a Basic Open Hearth Steel 0.1 % C 1911

Standardized Steel Bessemer 0.2 1907 Standardized Steel B.O.H. 1.0 1908

ss 9a Bessemer Steel 0.2 % C 1911 SS 16a Basic Open Hearth Steel 1.0 % C 1911

decades. At the beginning of the effort, the

chief of the Chemistry Division was Dr. William Noyes, and the analytical work at the Bureau was done by John Cain and three other chemists: Witmer, Isham, and Waters,

all of whom were probably industrial research associates.

By 1911, the catalog of reference materials had grown to 25 entries, all in support of

Development Association, and numerous

other groups. The Early Catalog

While the new concept of standard samples was sure to expand to many new types, that expansion did not produce a rational numbering system. From 1906 until 1910, numbers were not assigned, and the term stan- dard sample was not used. To help examine

Standard Reference Materials - The First
Tab[e 2. Other Examples Selected From the First 100 Standard Sample Numbers

SS 1 Argillaceous Limestone 1910 SS 43 Zinc (M.P. or F.RCirc.66) 1915?

SS 2 Zinc Ore 1919 SS 44 Aluminum (M.P. or F.R Circ.66) 1915?

SS 17 Sucrose (Stoichiometry) 1912 SS 45 Copper (M.R or F.RCirc.66) 1915?

SS 19-23 A series of carbon steels 1910 - 1920 SS 46 Portland Cement Sieve Test 1915?

SS 24 Vanadium Steel 0.15 % V 1910 SS 47 Portland Cement Sieve Test 1915?

SS 25 Manganese Ore 1910 SS 48 Benzoic Acid (Acidimetric) 1919?

SS 26 Crescent Iron Ore 1910 SS 49 Lead (Freezing Point) 1915?

SS 27 Sibley Iron Ore 1910 SS 50 Cr - W - V Steel 1921 SS 28 Norrie Iron Ore 1910 SS 52 Cast Bronze 1921 SS 29 Magnetite Iron Ore 1910 SS 53 Lead-base Bearing Metal 1921 SS 30 Chrome-Vanadium Steel 1912 SS 54 Tin-base Bearing Metal 1923

SS 31 Chrome-Tungsten Steel 1912 SS 57 Silicon Metal 1924

SS 32 Chrome-Nickel Steel 1912 SS 58 Ferrosilicon 1924

SS 37 Sheet Brass 1914 SS 60 Ferrovanadium 1924

SS 38 Napthaiene (Heat of Combustion) 1912 SS 80 Soda-lime Glass 1927

SS 39 Benzoic Acid (Heat of Comb.) 1912 SS 83 Arsenic Trioxide(Reductiometric) 1927

SS 40 Sodium Oxalate (Oxidimetry) 1924 SS 85 Aluminum Alloy (Duralumin) 1943

SS 42 Tin (M.P. or F.P.Circ.66) 1915? SS 98 Plastic Clay 1931

some of the materials comprising the first 100

certified, two tables are presented. In Table

1, the initial 14 metal reference materials are

listed, together with the designations of their

first renewals. Table 2 lists other examples drawn from the first 100 standard sample

numbers.

It is not clear that SS 7 Iron E was ever pro- duced as a "Standardized Iron E." The earli- est available certificate is for SS 7 without an

"a" designation, indicating that it may repre- sent the first time the material was pro- duced. Other metal standard samples

were produced in the 1910 to 1912 time peri- od, as is indicated in Table 2. It is also inter- esting to note that the elapsed time before

first renewal was typically only three to four

years, indicating heavy usage.

It is not surprising that limestone was an

early standard sample - it was useful as a refractory liner in metals production. The

first material to be certified that was completely unrelated to metal production was

sucrose as a calibrating material for polarimeters. "SS 2" was reserved for zinc ore as early

as 1910, although the first archived certifi- cate is dated 1919. Early additions to the cat- alog included primary chemicals to assist In calibrating titrations, and several standard samples for physical chemistry, especially for

calibrating calorimeters and thermometers. From the information in Table 2, it would

appear that there was a slowing of reference

material production during World War I. At

the time significant portions of the Bureau

Standard Reference Materials - The First Century
Table 3. NBS Programs and Staff (Noting Source of University Degree) - June 1904

Division I - Weights & Measures, Thermometry, Optics, Engineering Instruments

Louis Fischer Columbia University Llewelyn Hoxton University of Virginia Roy Ferner University of Wisconsin Nathan Osborne Michigan School of Mines

Charles Waidner Johns Hopkins University George Burgess University of Paris Hobart Dickinson Clark University Samuel Stratton University of Illinois Frederick Bates University of Nebraska

Perley Nutting Cornell University Albert Merrill Massachusetts Institute of Technology

Weights & Measures

Weights & Measures

Weights & Measures

Weights & Measures

Heat & Thermometry

Heat & Thermometry

Heat & Thermometry

Optics + Director. NBS

Optics

Optics Engineering Instruments

Division II - Electricity Frank Wolff

Francis Cady

George Middiekauf

Karl Guthe Edward Rosa

Ernest Dorsey

Frederick Grover Morton Lloyd Herbert Brooks

C. E. Reid

Franklin Durston Edward Hyde

Charles Sponsler

Johns Hopkins University Massachusetts Institute of Technology

Johns Hopkins University University of Michigan Wesleyan University Johns Hopkins University Wesleyan University

University of Pennsylvania Ohio State University Purdue University Wesleyan University Johns Hopkins University Pennsylvania State College

Resistance & Emf

Resistance & Emf

Resistance & Emf

Magnetism & Absolute Current Inductance & Capacity Inductance & Capacity Inductance & Capacity

Electrical measuring instruments

Electrical measuring instruments

Electrical measuring instruments

Electrical measuring instruments Photometry

Engineering Plant

Division III - Chemistry

William Noyes

Henry Stokes Johns Hopkins University Johns Hopkins University

staff were redirected to the war effort, a pre- cursor to the much larger dedication of per- sonnel (approximately 4000) to supporting

the military in World War II. Shortly after the

first war, "SS 85" was reserved for the alu- minum alloy "Duralumin" even though it was

not certified until 1943. An Unintended Consequence of Success in Reference Materials

The early work on Standard Samples at the Bureau had a profound impact on the later work of the agency. The U.S. Congress had

initially seen the agency as being primarily dedicated to construction and maintenance

of the physical standards of measurement. It seems quite clear that by looking at the earliest staff and their work of the Bureau (see

Table 3), that there was no plan to emphasize

studies in chemical and material fields further than what was needed to support programs

in instrumentation and metrology.

Despite the initial lack of agency emphasis on

materials efforts, the great success of the Standard Samples work weighed heavily in steering most of the growth of the new

agency into the direction of solving practical material problems and, in some cases, using

cutting edge instrumentation and methods.

Later amendments to the agency's organic

act recognized the Bureau's contributions to

materials characterization and development, and by 1950 provided specific authority to

certify and distribute reference materials as the leading U.S. authority.

Standard Reference Materials tury 7
.....^ Domestic Industries

Research at the Bureau occasionally provided

initiative for the production of a new SRM, and very often provided the tools needed to

certify materials with a reduced uncertainty. There are also cases where the production of an SRM inspired the start of an industry new

to the United States. A striking example of that occurred during World War I. Before

that war, the Bureau was distributing stan- dard samples of sugar for three important

applications: calibrating saccharimeters; cali- brating calorimeters used in measuring the heat content of fuels; and for use in differentiating bacteria in medical laboratory tests. Germany was the source of the pure sugars

that the Bureau characterized, certified, and

sold. When the war broke out and the materials were no longer available, the Bureau had to produce its own pure sucrose and dextrose. The German patents and production litera- ture were written so obliquely to protect proprietary rights from other producers that

reconstruction of the production processes required almost completely original research. The results were well worth the effort because the output was not only Bureau

Standard Samples, but also the technology

for producing low cost dextrose that launched a new domestic industry for American sugar producers and corn farmers.

William Meggers applied spectroscopy to physical and

chemical measurements.

The connection with instrument manufacturers is perhaps less direct; but nevertheless,

just as real. The ideas developed at the Bureau to solve all manner of analytical prob- lems were frequently blended with the work

of instrument makers to either create new

instruments or impact the progress in devel- opments of existing ones. Perhaps the tradi- tion started with recruitment from 1901 to 1904 of the first 26 professional staff members, seven of whom were from the Johns Hopkins University. Johns Hopkins was at the time an international leader in spectroscopic technology, so perhaps it was fitting that the

entire Chemistry Division professional staff of two were from Hopkins - William Noyes and

Henry Stokes. It was Noyes who first pro- duced atomic mass data at the Bureau,

reporting in 1907 the mass of atomic weighing of several elements, including hydrogen

at 1.00783.

In 1905, William Coblentz joined the staff and would serve the Bureau for the next 40

years. By 1914, William Meggers had also come from Johns Hopkins to join the staff, and would contribute for 52 years to a wide

variety of spectroscopic techniques that would later find their way into commercial

production.

Just as many of the early instrumental tech- niques for chemical analysis found their basis

in spectroscopy, so grew the need for refer- ence materials. This resulted from most spec- trochemical techniques requiring reference

materials as calibrants. Early Connections - Lasting Patterns One of the most interesting aspects found in studying the early technical efforts of the

Standard Reference Materials - The First Century
The Challenger

flight STS-6 provided

(National Aeronautics and Space

Administration) the 10pm

spheres for SRM 1960.

Bureau is the degree to which they established enduring programs of reference material production. Some of these cases are so obvious as to require no further explication, for example the program in cast iron stan- dard samples setting a 95-year-long pattern that lasts to the present. Some others are less obvious but no less interesting: Radioactivity - In 1911 Marie Curie pre- pared the first standard for activity as a sealed glass tube containing weighed

amounts of radium and radium salts and

characterized for its gamma ray count rate. The standard was accepted as an international standard and was maintained at the BIPMi France. A similar tube was prepared and calibrated with the one at BIPM for delivery to the Bureau in 1913, becoming

our Nation's first standard for radioactivity. This would serve as the start of a program

that would see the Bureau develop refer- ence materials to accommodate every

aspect of radioactivity measurement. An interesting repayment occurred in 1921

for Mme. Curie's earlier generosity to the

scientific community. By that time, she was

in need of additional radium to pursue her

investigations, but the material was too

expensive for her resources. On hearing of her plight, a group of American women

banded together and raised the funds necessary to purchase 1g of radium for Mme.

Curie. The material was certified by the Bureau for purity and activity and was pre- sented to the famous scientist by President Warren Harding.

Today, NIST has more than 70 radioactivity SRMs in the catalog. These cover a wide

range of applications, including certified

activity for radiopharmaceuticals, alpha

particle point sources, and gamma ray point sources.

Aviation/NASA - From the first days of

aviation, NBS took an active part in devel- oping the technology. Wind tunnels were

quickly constructed to develop improved

dii- airfoils and a special laboratory building

srn (the Dynamometer Building) was coness structed to research the weakest link in the whole enterprise, the engines. Absolutely the highest power-to-weight ratio was

needed, and that meant higher compression and extreme demands on fuels. Reference materials were issued for isooc- tane and n-heptane to serve as quality controls for the emerging aviation fuel industry. Calorimetry reference materials were

vital in designing the best fuels for piston,

jet and rocket engines.

trots for

try. Cal<

vital in c jet and r

In 1915 the National Advisory Committee

for Aeronautics (NACA) was formed; the Bureau had a leading place in the committee. The other agencies, including the Army and Navy, did not have aeronautical

facilities, so the laboratory work fell to the Bureau. In late 1932, President-elect Roosevelt proposed folding NACA into the

Bureau. That proposal was never carried

out, but in 1946 Hugh Dryden, one of the

nation's top theoretical aerodynamicists,

left the Bureau to direct all research at NACA. He subsequently led the transfor- mation of NACA into NASA in 1958.

Later, reference materials of many types contributed to aerospace development. Aluminum alloys, and high-strength alloys were needed for skins and airframes. High temperature alloys were needed for jet and rocket engine hot-section components. NDE (non-destructive evaluation) reference materials were needed for monitoring part reliability in service. Every ref- erence material in support of electronics technologies has a carry-over application in

The Bureau International des Poids and Measures (BIPM) is located in Sevres, a suburb of Paris. It has the task of ensuring worldwide unifacation of physical measurements.

Standard Reference Materials - The First Century 9
In the mid-1980s, the Standard Reference

Materials Program organized the certifica- tion campaign for the first commercialized

material produced in space - a length stan- dard at microscopic scale. Perhaps it was

the long-term connections between the two agencies that gave NASA the confi- dence in NBS to carry out the novel project. The material certified was SRM 1960 Nominal 10 pm Diameter Polystyrene Spheres (certified as 9.89 [sm ± 0.04 pm). John Vanderhoff of Lehigh U. and Dale

Kornfeld of NASA had teamed together to produce spheres in "Monodisperse Latex Reactors" aboard five missions in 1982 and

1983. The missions were STS 3-4 and STS 6-

8, with the spheres for SRM 1960 being

produced aboard the Challenger's STS 6

mission. After the Challenger disaster, George Uriano (SRM chief, 1979 - 1983) served as a Congressional staff member in the investigation of the tragedy. Forensic "Signatures" - Just as one could

say that NASA was a Bureau spin-off, the same is true for the crime laboratory at the

Federal Bureau of Investigation (FBI). The FBI had no crime

lab prior

to 1932, when the Bureau assisted in its development. Before that time, the Bureau did laboratory work as a service to the FBI, including the famous Lindbergh

kidnapping case in 1932. The Bureau had

significant impact on the case through the handwriting analysis of Wilmer Souder who conducted forensic investigations for the Bureau from 1913 until 1954. Most forensic signatures are not in handwriting. Perhaps more important are bullet lead markings, broken glass matching,

breathalyzer tests, drugs of abuse in urine, and DNA profiling. Over the past 60 years, NBS/NIST has certified reference materials

for all these signatures. Proximity Fuse/Electronics - A major NBS contribution to the ordinance effort for World War II was the development of the proximity fuse that caused shells and bombs to explode at a predetermined

point above the ground. By the 1950s, all such direct military work was transferred out of the agency. However, a great deal of the technical work associated with the

fuses was to miniaturize and harden the

associated electronic circuitry. The funda- mental parts of that work stayed at NBS

and stimulated the development of a number of SRMs.

Today, the SRMs related to electronics cover a wide array, from the composition

of solder alloys to the transmission properties of complex optoelectronic devices. Perhaps most basic are those for the conductivity and resistance of a variety of metals and, especially, silicon. Residual resistivity ratio SRMs are also available for silicon. Dimensional metrology is so critical to semiconductor manufacture quality assur- ance that NIST has developed photomask

linewidth artifacts, such as SRM 475, for

calibrating optical and scanning electron microscopes, and has developed a range of

thin film thickness SRMs for ellipsometry.

he First Century
Highways for a Nation - When Dwight

Eisenhower became president in 1953, one of his programs was to link every part of the Nation with a modern high-speed

highway network, the Interstate Highway

System. The Bureau of Public Roads at the time had no laboratory, so it funded sig- nificant levels of work at NBS, including

efforts on Portland cement that would

eventually be organized as the Concrete and Cement Research Laboratory. Field laboratories for testing concrete were

maintained in San Francisco, CA;

Riverside, CA; Denver, CO; Alientown, PA; and, Seattle, WA in addition to the main NBS facility at Connecticut Avenue and

Van Ness Street, in Washington, D.C.

What remains at NIST today are the complex

metrology issues associated with healthrelated measurements in such areas as the environment, clinical chemistry, pharmaceutical measurements, food labeling, and nutri- tional studies. The general SRM categories

for these are listed in Table 7. For these

fields, NIST has excelled in providing hundreds of well-selected and characterized SRMs. Environmental natural matrix materials are covered with a wide variety of solids, liquids, and gases being covered for both

inorganic and organic constituents. More than 35 differ- ^

ent SRMs serve to validate clinical laboratory determinations. Most analytical instru- ments found in pharmaceutical laboratories have one or more SRMs available to pro- vide measurement traceability. Some of the newest BHHlH

SRM work has been dedicat- iLg

ed to food analysis, with kS^^

about 30 types of applicable 1^

SRMs now available. >

The quality of the roads constructed would

rest in part on the accuracy with which the

Portland cement was formulated to meet

local gravel, temperature, and humidity

conditions. NBS already had experience

with Portland cement reference materials, so the highway program provided need and opportunity to expand the SRM cata- log with more than a dozen new offerings

for cement composition, particle size, and

rheology. Consumer Protection/Health - While the Bureau has produced many services and

publications of interest to consumers, it has never been primarily a consumer products

laboratory. Indeed, if described beyond

being a metrology laboratory, the more

comfortable niche would be as an industri- ally-oriented laboratory. When the Consumer Product Safety Commission

(CPSC) was formed in the 1960s, it had no

laboratory and depended entirely upon

NBS for laboratory support. During the

1970s, the level of work had increased sufficiently that CPSC could start its own laboratory with the help and transfer of many

NBS staff members.

A Team Approach - From

the earliest days of cooperation with the American

Foundrymen's Association, the 'sj^ Bureau has built on the success of steady growth in cooperation with technical societies and standards organizations. Perhaps no part of Government is as wel- come in the activities of such bodies. This means NIST is usually the agency most

likely to be trusted as an "honest technical broker" of ideas and programs. Even a

partial list of cooperating organizations would need to include the American

Society for Testing and Materials (ASTM)

International, the Society of Automotive

Engineers (SAE), the Institute for Electrical and Electronic Engineering (IEEE), the

' REFERENCE MATERIA 2383 ^ Baby Food

Composite

^ ffi ip.^ ' i ANn.VKUS .VND TECHM>1 ^THERSBUKi;. Ml) 208SW

Standard Referen The First Century 11
American Chemical Society (ACS), the American Ceramic Society (ACS), the

Institute for Textile and Color Chemists

(ITCC), the American Iron and Steel

Institute (AISI), the Copper Development

Association (CDA), the College of American

Pathologists (CAP), and the American

Association of Clinical Chemistry (AACC).

NIST has had joint programs to develop or share SRMs with every one of these organizations and many more besides. See Appendix A. Continuing Efforts Between the two World Wars, Standard Sample activities grew slowly, but steadily. Industrial needs for materials for chemical

analysis were the major, almost exclusive, impetus. Starting in World War II the needs

for Standard Samples began to grow and

change.

As a primary national laboratory for materials research, NBS contributed to the Manhattan Project through uranium

studies. Among other accomplish- ments, NBS scientists carried out pioneering work in the

separation of uranium

isotopes and devel- oped Standard Samples for X determining the

isotopic composition of materials containing uranium and plutonium. These materials continue to serve the country today for the

accurate assay of reactor fuels.

After the war, breakthroughs in the fields of

electronics, and polymer research, and the spread of spectrometric instruments brought new demands for reference materials. By the

1950s, special hydrocarbon blends were avail- able for calorimetry and Standard Samples were being certified for such properties as pH, melting point, and radioactivity. New

high temperature and super strength metal

alloys were needed to meet the demands of innovations in jet aircraft and rockets. The 50s and 60s saw an acceleration of efforts to certify reference materials; 582 types were

available in the catalog in 1959. It was during this period that the Bureau began to

transfer some of its efforts in reference materials to other institutions. This will be dis- cussed in more detail in the section: "Closing the Cycle." During the 1960s, NBS realized that SRMs 2 were becoming increasingly important to industry and that industrial demand would continue to grow. The

Bureau also recognized the potential contri- bution SRMs could make in solving measure- ment problems in emerging areas of national need, such as clinical and environmental

chemistry.

To appreciate the place and importance of SRMs in the work of the Bureau at the midpoint of its centennial requires a closer look

at events impacting the agency around the middle of the 20th century.

2 The term "Standard Reference

Materials," and the acronym "SRM"

were introduced into use by NBS in 1965. The term and acronym were K

later registered with the U.S. Patent and Trademark Office.

cl Reference Materials - The First Centun/
Mid-century Turmoil Two separate, initially very damaging, tribu- lations fell upon the Bureau between 1948 and 1952. Eventually, the agency would

recover from these two blows with a firmer

resolve and an even stronger sense of mission. Before that happened, two directors would face disgrace and the budget would

suffer serious decline. One of the strongest elements of the Bureau's program was its Standard Samples Activity, and we will see how it was a major contributor to restoring both fiscal and public relations health to NBS. Edward Condon, fourth director of NBS, was

perhaps its most eminent director in terms of

scientific achievement. He was a noted theoretician with great insight in atomic and

nuclear physics, and provided great service to the Nation during World War II. Prior to

leading NBS, he worked at Los Alamos on development of the atomic bomb and served with Chairman Lyman Briggs (third NBS director) on Committee S-1 to directly advise

President Roosevelt on atomic and nuclear

issues, including the decision to build the atomic bomb.

After the war, he continued to advise

President Truman and the Congress. As part of that advice, he strongly advocated the for- mation of the Atomic Energy Commission to move control of nuclear activities from the

military to the civilian sector. He became a spokesman for peaceful uses of the atom to

benefit the whole world. Neither of these

positions were popular with the military, which had a strong post-war victory standing, or with the House Unamerican Activities Committee. In 1948, that committee charged Condon with being a risk to National security. No charges were ever proved, but the committee denied the director opportunity

to address the charges and he left NBS in 1951 to become the director of research at

(top) Aerial view of

Gaithersburg Campus (1999). (bottom) Aerial view of Boulder Campus (I960's).

Corning Glass, in all, it was one of the sadder

episodes of "witch hunting" seen in our

country. The second turmoil also began in 1948, but it peaked in 1952, thus impacting the fifth director, Allen Astin. This cloud over the Bureau arose from the assignment to test many kinds of commercial products. One of

these, a battery additive named AD-X2, was

found by NBS to be ineffective. Less controlled tests in other places showed some promise for the additive, so the developer (and more

significantly, his Congressman) attempted to dis- credit NBS results. Astin was well versed in electrical engineering and stood behind the results of his technical staff through a firestorm of Congressional hearings and unmeasured

personal attacks.

Finally, the

Secretary of Commerce "fired"

Astin. Now, it was

the turn of the

technical staff to stand behind their director.

Hundreds told the

President that they would go if Astin went. Based on additional data from other

sources and the unanimous advice of the NBS Visiting Committee, the

Secretary retained

Dr. Astin as direc- tor and he served with distinction

until retirement in 1968, foliowinc;

Standard Reference Materials - The First Century
Table 4. NBS Funding for Selected Years Year Appropriation ($ millions) 1946 3.6 1948 7.1 1950 8.5 1952 7.8 1954 5.7 1956 7.4 1957 8.4 + 2.8 WCF = 11.2 1958 9.7 + 2.5 WCF = 12.2 1960 20 1970 > 40

Comment

Condon era begins, need for war $ replacement House Unamerican Activities Comm. / Condon

Working Capital Fund (WCF) authorized

Astin era begins, peak of AD-X2 affair Kelly report will shape future budgets

Budget still below 1949 level of $ 8.7 million WCF implemented, 10yr funding crisis ended

Sputnik launched

First impact of Sputnik on budget

Final budget developed by Dr. Astin

completion of the Boulder laboratory (1954) and of the Gaithersburg facility (1966).

The two episodes could only adversely affect the budgets from 1952 through 1956. More than 90% of NBS funding during the war years was

from defense sources, and that was being reduced in peacetime. Turmoil had struck just when it was not needed. Table 4 provides a snapshot of the seriousness of the situa- tion. In reading the table, it is important

to note that the budget process is slow and

usually follows impacts by about two years.

Dr. Astin's first appropriation from Congress was for 1954, covering July 1, 1953 through

June 30, 1954, and at $5.7 million was the

smallest in the previous seven years. A New Beginning

One response of the Secretary of Commerce

to the AD-X2 difficulty was to commission a high- level assessment of the work and mission of NBS. The study was chaired by Mervin

Kelly, president of Bell Telephone

Laboratories. On October 15, 1953, the committee issued recommendations that would

14 Standard Reference Materials - The First Century
"li

shape the Bureau for the next 35 years. The

report would become known as the Kelly Report, and it singled out two parts of Bureau work to praise: basic research in metrology and the value of the standard samples program. The Kelly Report con- tained ten recommendations that are grouped into three categories and presented

in Table 5, where the numbers indicate the sequence of the recommendations as found

in the report.

It would be overreaching to say that NBS

Standard Samples rescued the Bureau at the

century's mid-point, but it would be fair to say that they had made a very impressive mark and

again had a prime role in shaping the Bureau's new mission. New emphasis was given to moving the development of standard samples beyond chemistry alone. The new approach

started slowly. Then, in 1964, the Office of

Standard Reference Materials was

established and given the

responsibility for directing

all SRM activities. Table 6 provides a list of the

leaders for reference material activities both before and

after creation of the new office. JfeMM^M

Previously the indi- vidual technical divi- flficQ

sions had managed

separate compo- ^^^^H

nents of the SRM i^^^^l

program with coor- ^^^^^^H

dination through

the Analytical J^^^^l

Chemistry Division. ^^^^H

With the establish- ^i^H

ment of a new 9

Table 6. Leaders of the Standard Sample/ SRM Production Activities at NISI 1905 - 2001

Year 1905 Name

John Cain

Title Research Associate 1918 Gustave Lundell Chief

1940 Harry Bright Chief 1950 Harry Bright and

Bourdon Scribner ChiefChief 1960 John Hague

Bourdon Scribner Chief

Chief 1964 Wayne Meinke Chief 1969 J. Paul Call Chief 1979 George Uriano Chief 1983 Stanley Rasberry Chief 1991 William Reed Chief 1994 Thomas Gills Chief 2000 Nancy Trahey-Bale Chief 2002 John Rumble Jr. Chief

Organization Chemistry Division

Analytical Methods &

Standard Samples

Metal 8r Ore Analysis, Standard Samples

Analytical Chemistry

Spectrochemistry

Analytical Chemistry

Spectrochemistry

Office of Standard Reference Materials

Office of Standard Reference Materials

Office of Standard Reference Materials

Office of Standard Reference Materials Standard Reference Materials Program

Standard Reference Materials Program

Standard Reference Materials Program

Standard Reference Materials Program

Standard Reference Materials - The First Century 15
office, a number of new

thrusts were developed. New

program areas were identified and initi- ated, including the start of what was to become a major effort in developing SRMs

for clinical chemistry. For a list of some of the key SRMs beyond the first 100, see Appendix B. Through the 1970s, the program had its most

productive decade in terms of the develop- ment of both numbers and types of SRMs. Over 600 new SRMs were certified during

that period and about 250 were discontin- ued. By 1979, 1,060 types appeared in the

catalog. Typical of the research activity into new SRM types in this period was a whole array of environmental natural matrix

materials certified for inorganic constituents. Leading the list, and arguably the most

important materials of their era, were SRM

1571 Orchard Leaves, SRM 1645 River Sediment, and SRM 1648 Urban Particulate Matter. John Taylor directed the certification of these materials. The river sediment was

prepared from material dredged from the

Indiana Harbor Canal, near Gary, Indiana. Heavily loaded with toxic metals the material served as the initial benchmark for environ- mental studies in the field. It is also important to note from an analytical perspective, that these were the first environmental

matrix materials to receive extensive application of the new isotope dilu- tion mass spectrometry method developed by NBS, and which was also used to good effect in the certification of SRM 909 Human Serum.

During the 1980s, the many

advances in inorganic environ- mental reference materials were extended by the addition

of SRM certifications for organic

analytes of environmental health concern. Some of these included PCBs in human serum, in oil, and in sediments. Also made available were SRMs with certified values for a variety of forms of dioxin, polynuclear aromatic hydrocarbons, halocarbons, chlorinated pesticides, and other priority pollutants.

Food-based SRMs began coming into the

inventory in the 70s and 80s with the intro- duction of such materials as wheat flour, rice flour, and freeze-dried bovine liver, oyster tis- sue, and spinach leaves. The SRM efforts toward better coverage of food types really have seen the most progress in the 1990s, with work being dedicated to certifying mixed diet food materials, infant formula, and individual foodstuffs for vitamin content. Efforts along these lines are sure to continue into NIST's next century. Today's Catalog

As impressive as is the history of SRM production and certification, perhaps even more

impressive is the work summarized in the cur- rent catalog and in the work program for future certification. Table 7 provides the cat- egory names that cover the approximately 1400 SRMs and other reference materials

available in the SRM catalog for 2001, avail- able under the NIST home page on the World Wide Web as well as in printed form.

Standard Reference Materials - The First Century
Wide dissemination of information on avail

ability, including exhibits at 5 to 10 confer ences each year, helps the program distribute more

than 35,000 units of

material to about 10,000 customers

Approximately one-third

of each year's sales are delivered abroad. Closing the Cycle

As many types of reference

materials matured and NIST

interests turned to other

technologies, efforts have been made to find institu- tions willing to receive transfer of the materials and

responsibilities. This is essential to permit reallocation of

scarce resources to fund new efforts.

During the 1 950s and 60s, some of the first of these transfers took place. The extensive hydrocarbon blend project was transferred

to the American Petroleum Institute. Color and fading SRMs were transferred to the American Association of Textile Chemists and

Colorists, and viscosity materials went to Carnegie-Mellon University. During the

1980s, in part for security reasons, the SRMs

for uranium and plutonium were transferred

to the New Brunswick Laboratory of the US Department of Energy located at Argonne

National Laboratory. At the beginning of the

1990s, NIST was closing out its work on rub- ber compounding so about a dozen types of rubber compounding, SRMs were transferred

to ASTM. These are a few of many examples

of "passing the baton" on reference materials that NIST can no longer support.

Not all the transfer efforts have involved

actual movement of the materials. Most of the metal materials that have figured so

Table 7. SRM Categories for 2001

Health and Clinical industrial Hygiene

Environmental Food and Agriculture High Purity Materials

industrial Materials Engineering Materials

Physical Properties

Radioactivity

heavily in the early devel- opment of the Standard sample and SRM pro- grams, have remained at

NIST, but much of the certification effort on

renewal lots is only undertaken by laboratories organized in cooperation with ASTM. It is highly likely that the trend will be for NIST

to continue to seek partners in industry, universities, or other government agencies to provide homes for SRMs and RMs being

closed out at NIST. Benefit/Cost

The annual cost each year for all types of measurements in the United States is counted

in the hundreds of billions of dollars. A small view of the scale and vigor of the activity in analytical chemistry alone is seen each year at the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, where

about 30,000 conferees gather, they represent perhaps a tenth of their colleagues working in the field. Those who have attended this con- ference for many decades will recognize the many changes in the field that have brought

significant improvements in effectiveness and

efficiency to most types of chemical analysis. The driving forces behind these changes have

included the rapid and far-reaching develop- ment of instrumentation, the improvement of

Standard Reference Materials - The First Century
analytical methods, and the avail- ability of Standard Reference

Materials from NIST and sec- ondary suppliers.

It is not hard to calculate that an SRM contribution to measure- ment improvement, even as small as 0.1 %, would save companies which measure hundreds

of millions of dollars each year - easily justifying the approxi- mately $10 million spent annually to buy SRMs. Client demand

for ever increased numbers of types provides a qualitative indi- cator of the program benefits. The demand requires careful pri- oritization, for it greatly exceeds each year's SRM budget. Table 8 summarizes the approximate number of SRM types

available at ten-year intervals. The table data are not exact since no hard data were

recorded for most of the intervals. However,

several sources have been studied and the

values are probably dependable, with an

uncertainty of less than 10 % of each value. Reasons for the ambiguity include discontin- uation of SRMs (with perhaps 1000 types having been discontinued over the history of the program) and an uncertain number of materials listed in catalogs being out of stock at a given time. Additionally, SRMs have not been numbered sequentially, complicating

historical counts. What is harder to quantitate is the social contribution made by SRMs. In a study by the

Research Triangle Institute on the economic

impact of SRMs for sulfur in fossil fuels, three economists led by Sheila Martin determined

that the group of SRMs had a benefit/cost

ratio of 113, and a social rate of return of more than 1,050 %. Similar conclusions have been reached at other times and in other

studies with regard to a variety of SRMs. While not as quantifiable, there are major

ur 11^Ma

benefits to people dependent on good clinical measurements; for example, the child whose epileptic seizures are better controlled by measure- ments improved with SRMs. In another

example, cholesterol measurement uncertainties have been reduced from 20 % in the

1970s to 5 % in the 1990s, again with the

help of SRMs. It is clear that customers' demands for more and better SRMs are unrelenting. Despite the common complaint "SRMs cost too much," customers continue to buy them in quantities adequate to fund

future certification programs.

Table 8. Approximate Number of SRM types

Available by Decade

Year Number Year Number

1910 20 1960 400

1920 50 1970 600

1930 90 1980 1100

1940 200 1990 1200

1950 250 2000 1300

Standard Reference Materials - The First Century
Collaboration Around the World

Especially over the last five decades, the Bureau has nurtured strong ties tor international cooperation. About 25 years ago, the International Organization for Standardization (ISO) accepted as a Council Committee, a group to work on reference

materials. The committee was first referred to as REMPA and very quickly had a change in name to ISO Committee on Reference

Materials (REMCO). Strong impetus for its founding and early success was supplied by NBS staff members such as Bill Andrus, Paul

Call, and George Uriano. REMCO has become

the focus for defining the terminology and

practices of reference material certification and use.

NIST has participated in many bilateral and

multilateral cooperations. Some of these have had a goal of certification of a specific SRM or groups of SRMs, while others have been oriented toward helping other countries get started in the field. As an example

of the latter, NIST hosted approximately 200

chemists from China over the first 15 years following renormalization of relations between the two countries. Analysis of SRMs

was part of the effort for many of the

chemists. Some of them, on return to China,

established a very vital program in production of reference materials. On a smaller scale, cooperative

projects have been s with Mexico folio the implementation

of the North American Free

Trade Agreement and agreements for cooperation in metrology. Additional efforts have been carried out with France, the United Kingdom, Germany, Japan, Egypt, Poland, and several other countries. Some of the most effective collaborations are those aimed at gathering data to characterize proposed new reference materials. In recent

years these have included many countries contributing to the development of SRMs. A

few examples include the certification of

infant formula and mixed diet SRMs, and also a large suite of food RMs from Canada. Other

efforts have included contributions from most

of the world's industrialized countries. An

earlier example occurred in the late 1970s. NBS partnered with 70 individuals from 22

organizations in the U.S. copper industry and ASTM to develop a series of unalloyed copper

SRMs. Robert Michaelis, Jerry Hust, and Lynus Barnes directed the effort which received not

only a large measure of U.S. industrial support, but also the contribution of data from

Canada, South Africa, South America, and the European contributors. Conclusion

The aim of this brief account has been to highlight a few of the many contributions that NBS-NIST has made

through the

certificaference Materials - The First Century
and distribution of reference materials. The

selection of examples cited only begin to probe the surface and cannot do real justice to the program in its entirety over almost 100

years. Many chemists will, however, relate to the great feeling of success that comes when

analyzing an SRM from NIST and obtaining the certified values or discovering a disagree- ment, thereby preventing the propagation of an error!

Standard Samples and SRMs have been among the most widely known and distrib- uted measurement artifacts of all the

NBS/NIST contributions, with several million

units having been circulated in the first 100

years. Few are the scientists around the world who have not heard of SRMs and the Nisr , Standard I Reference jB

Materials fi

(301)975-6776

TM

value they provide for validating a method or

calibrating an instrument. By promoting and

sharing the ideas and technologies of reference

material development, the Bureau has been a good neighbor in the world community.

Standard Samples and SRMs have represent- ed some of the finest efforts produced by

NIST. By successfully solving material-related problems and bringing attention to those

successes, the work on reference materials has had a major effect on the development

of the early Bureau's selection of work pro- grams and ultimately its character as a worldclass metrology organization. It has been an

exciting century for the field of reference

materials in support of analytical chemistry and the other sciences. Perhaps it will be seen

in another 100 years as a worthy introduction to the even greater things that are yet to come for NIST SRMs.

I www.nistgov/srm

For those inclined to speculate about the future, a few of the author's notions are tabulated in Appendix C. The only

certainty about them is that they are uncertain. They are most likely to be seen in retrospect as too conservative.

20 Standard Reference Materials - The First Century
Appendix A Cooperation With ASTM in Standard Reference

Material Development

The NBS/NIST reference materials program

has, since it began to develop reference materials in 1904, benefited from close cooperation with many of the nation's finest technical

societies and associations. It is clear today

that without this cooperation, the program would either never have started or would be

vastly different and probably greatly diminished in size and scope. None of the alliances has been more far reaching and had greater impact than the one with the American

Society for Testing and Materials (ASTM).

Starting before the second world war, the

cooperation has arranged for the shared development of more than 1000 Standard Samples and Standard Reference Materials. Formal Research Associate Programs have

posted ASTM staff at NIST to participate

directly in the preparation and measurement

of candidate materials and, perhaps even more importantly, to arrange for the technical assistance of many contributors from hundreds of industrial laboratories. Today, ASTM

E01.94, Subcommittee on Development of Reference Materials for the Chemical Analysis of Metals, Metal-Bearing Ores and Related

Materials, meets semiannually to prioritize

requests to NIST for new and renewal refer- ence materials and to cooperate in their development.

In 1987, the author prepared a list of selected

instances where SRMs are specified for use in ASTM technical standards. The list is by no means complete (for example ASTM D02.SC3, Subcommittee on Elemental Analysis,

recently included SRM 1848 "Lubricant Additive Package" in new standards

for motor oil test methods), but is given below to indicate the scope

of SRM inclusion in ASTM stan- dards.

During its first century, NIST has provided technical staff expertise

in ASTM, filling as many as 800 committee assignments in some years. Several staff members have served as directors on the ASTM Board. The former

chief of the Standard Reference Materials Program, Nancy Trahey-Bale, was one of

those, having served as treasurer and later as chairman of the Board of Directors for ASTM

in 1993.

INTERNATIONAL

Standards Worldwide

Standal Materials - The First Century 21
Selected Examples of SRM Incorporation in ASTM Standards (as of 1987) ASTM

STANDARD TEST NIST SRM

C 204 Cement Fineness (Blaine) 114n Portland Cement

C 115 Cement Fineness (Wagner) 114n Portland Cement C430 Sieve Residue 114n Portland Cement

C 336 Glass Annealing and Strain Points 711 and 717 Glass Viscosity C338 Glass Softening Points 711 and 717 Glass Viscosity C657 Glass Electrical Resistivity 624 Glass Electrical Resistivity C770 Glass Stress Optical Coefficient 708 and 709 Glass C829 Glass Liquidus Temperature 773 Glass Liquidus Temperature D 1238 Melt Flow Rate (Plastic) 1475 and 1476 Polyethylene D 1505 Density (Plastic) 1475 and 1476 Polyethylene D 1434 Gas Transmission Rate (Volumetric) 1470 Polyester Film D 1434 Gas Transmission Rate (Manometric) 1470 Polyester Film D 3985 Gas Transmission Rate (Coulometric) 1470 Polyester Film D 1646 Mooney Viscosity 388m Butyl Rubber D 2268 Chemical Analysis of Fuels 1816a isooctane D 3177 Sulfur Analysis in Coal and Coke 2682-2685 Sulfur in Coal D 4239 Sulfur Analysis in Coal and Coke 2682-2685 Sulfur in Coal D 2795 Analysis of Coal and Coke Ash Soda Feldspar

E 27 Analysis of Zinc and Zinc Alloys 94c Zinc Base Alloy

E 129 Analysis of Thermionic Nickel 671-673 Nickel Oxide

E 322 Analysis of Steels and Cast Irons numerous steel/iron SRMs cited E 539 Analysis of 6AI-4V Titanium Alloy 173 and 654a Titanium Alloy

E 162 Flame Spread Index 1002c Surface Flammability

E 648 Critical Radiant Flux 1012 Flooring Radiant Panel

F 746 Pitting and Crevice Corrosion 1890-1891 Crevice Corrosion

Standard Reference Materials - The First Century
Appendix B Key NBS Reference Materials Beyond the First 100

Numbering of Standard Samples and

Standard Reference Materials has been

assigned according to several different sys- tems during the first century of production and certification. Almost all of the first 100 SRMs were completed before 1930 and

assigned numbers more or less in sequence,

with the exception of the first four "standard samples" (as was discussed in the main text). Occasionally a number was reserved for a certain SRM, such as 85 for aluminum alloy (Duralumin) first issued in 1943, that had a delayed issue or was not issued at all. In a few cases, numbers for unissued materials and SRMs that were issued but discontinued have been reused for different materials.

Current practice retires the numbers of dis- continued materials. Typically, when a given

lot of material for an SRM is exhausted and

replaced with a new lot, new certification measurements and a new certificate are

required. The new lot of the SRM retains its numerical designation and a lower case let- ter is appended or changed to denote the

lot. For example, SRM 916a Bilirubin is the

first reissue (second material lot) of SRM 916

Bilirubin, while SRM 955b Lead in Blood is the third lot of that material.

The table that follows sketches the development

of SRM types over time by listing the date of ini- tial issue for selected key materials. The list is intended only to be representative as it includes but a small percentage of all materials issued. Selection for the list typically indicates the SRM is an early member of a given material type.

Selected Key NBS/NIST Reference Materials Beyond the First 100 SS/SRM

102

103

112

113 119

TITLE

Silica Brick Chrome Refractory

Silicon Carbide

Zinc Concentrate Chromel P

DATE

1932 1934

1937

1941 1935

APPLICATION

Composition

Composition

Composition

Composition

Thermometry

120

136 140

147 154

Phosphate Rock

Potassium Dichromate

Benzoic Acid

Triphenyl Phosphate

Titanium Dioxide

1939 1948

1942

1969

1943

Composition

Oxidimetric Microcombustion

Microanalytical Composition

160

162 164

165

173

Stainless Steel 19Cr-9Ni-3Mo

Ni-Cu Alloy Mn-AI Bronze

Glass Sand

Titanium Base Alloy (6AI-4V)

1949

1949

1951 1948

1957

Composition

Composition

Composition

Composition

Composition

Standard Reference Materials - The First Century 23
(Continuation of Table) Selected Key NBS/NIST Reference Materials Beyond the First 100 SS/SRM TITLE DATE APPLICATION

187 Borax pH Standard 1947 pH Standard 303 Burnt Sienna 1944 330 Copper Ore Mill Heads 1973 Composition

331 Copper Ore Mill Tails 1973 Composition

343 Stainless Steel 16Cr-2Ni 1962 Composition

349 Waspalloy 1959 Composition 475 Optical Microscope Linewidth Measure 1981 480 Electron Microprobe Standard (W-20Mo) 1968 Composition

482 Gold-Copper Wires for Microprobe 1969 Composition 484 Scanning Electron Microscope Mac|nication 1977 Length 485 Austenite in Ferrite 1970 Composition

592 Hydrocarbon Blend No. 1 1961 Composition 600 Bauxite 1988 Composition

601 Spectrographic Aluminum 1951 Composition 610 Trace Elements in Glass Matrix 1970 Composition 620 Soda Lime Flat Glass 1972 Composition

621 Soda Lime Container Glass 1975 Composition

623 Borosilicate Glass 1976 Composition

633 Portland Cement 1974 Composition

640 Silicon Powder for X-ray Diffraction 1974 Lattice Pattern 671 Nickel Oxide 1960 Composition 674 X-ray Powder Diffraction 1983 Intensity 679 Brick Clay 1987 Composition

680 High Purity Platinum 1967 Composition

702 Light Sensitive Plastic Chip 1966 Fading 705 Polystyrene 1963 Molecular Weight

740 Zinc Freezing Point 1970 Temperature

762 Magnetic Moment * Nickel Disk 2000 Magnetic Moment

767 Superconductive Fixed Point 1974 Temperature

772 Magnetic Moment - Nickel Sphere 1978 Magnetic Moment

781 Molybdenum - Heat Capacity 1977 Heat Capacity 870 Column Performance for LC 2000 Efficiency 877 Chiral Selectivity for LC 2000 Selectivity 909 Human Serum (Clinical) 1980 Composition

911 Cholesterol (Clinical) 1967 Composition

912 ^ Urea (Clinical) 1968 Composition

913 Uric Acid 1968 Composition 914 Creatinine 1968 Composition 916 Bilirubin 1971 Composition

927 Bovine Serum Albumin (Total Protein) 1977 Composition

Standard Reference Materials - The First Century
(Continuation of Tabfe) Selected Key NBS/NiST Reference iVIaterials Beyond the First 100 SS/SRM TITLE DATE APPLICATION

930 Glass Filters for Spectrophotometry 1971 Transmittance 934 Clinical Laboratory Thermometer 1974 Temperature

945 Plutonium iVIetal 1971 Assay

946 Plutonium isotopic 1971 Composition

955 Lead in Blood 1984 Composition

968 Fat Soluble Vitamins in Human Serum 1989 Composition

987 Assay-lsotopic Strontium 1971 Assay & Composition 1001 X-ray Film Step Tablet 1973 Optical Density 1003 Calibrated Glass Spheres 1965 Length

1008 Photographic Step Tablets 1971 Optical Density 1010 Microcopy Resolution Test Charts 1963 Resolution 1013 Portland Cement 1962 Composition

1083 Wear Metals in Lubricating Oil 1985 Composition

1244 Inconel 600 1984 Composition

1246 Incoloy 800 1984 Composition

1261 AISI 4340 Steel 1970 Composition

1321 Coating Thickness - Nonmagnetic on Steel 1988 Length

1387 Coating Weight - Gold on Nickel 1985 Length

1400 Bone Ash 1992 Composition

1470 Polyester Film - Gas Transmission 1978 Transmission 1475 Linear Polyethylene 1969 Molecular Weight

1479 Polystyrene 1981 Molecular Weight

1491 Aromatic Hydrocarbons in Hexane/Toluene 1989 Composition

1492 Chlorinated Pesticide in Hexane 1989 Composition

1511 Multi-Drugs of Abuse in Freeze-dried Urine 1994 Composition

1515 Apple Leaves 1991 Composition

1521 Boron-doped Silicon Slices for Resistivity Meas. 1978 Resistance 1523 Silicon Resistivity for Eddy Current Testers 1985 Resistance 1544 Fatty Acids 8i Cholesterol in Frozen Diet 1996 Composition

1546 Meat Homogenate 2000 Composition

1547 ^^Peach Leaves 1991 Composition

1548 Total Diet 1990 Composition

1549 Non-fat Milk Powder 1984 Composition

1563 Cholestrol & Fat-Soluble Vitamins in Coconut Oil 1987 Composition

1566 \\Oyster Tissue 1979 Composition

1567 Wheat Flour 1978 Composition

1568 Rice Flour 1978 Composition

1570 Trace Elements in Spinach 1976 Composition

1571 Orchard Leaves 1971 Composition

1577 ^^ovine Liver 1972 Composition

Standard Reference Materials - The First Century 25
(Continuation of Table) Selected Key NBS/NIST Reference Materials Beyond the First 100 SS/SRM TITLE DATE APPLICATION

1579 Powdered Lead Based Paint 1973 Composition

1580 Ornani^c Wl^ClKII^S inIII CliJilo Allelic Oil Wll 1980 Composition

1581 PoiychloriiidtiGcl BiphGnyls in Oils 1982 Composition

1582 Petroleum Crude Oil 1984 Composition

1583 ClorindtGci Pesticides in 2r2f4~'trinie'tliylpentdne 1985 Composition

1584 Priority Pollutant Phenols in Methanol 1984 Composition 1588 Or^anics in Cod Liver Oil 1989 Composition

1589 Polychiorinated Biphenyls in Human Serum 1985 r'omnncif'ion \>UIII|JU3l IIUII 1590 9iaijiiizea Wine 1980 Alcohol Content

1598 Inorganic Constituents in Bovine Serum 1989 Composition

1599 Anticonvulsant Drug Level Assay 1982 Assay

1601 Carbon Dioxide in Nitrogen 1973 Composition 1604 Oxygen in Nitrogen 1968 Composition

1610 U%/rli*n^A nyui vvdivhrkn uvrii iii in nii Air 1969 ^nmnncitinn \h\JIiI|JU9I IIUII 1614 1985 Composition

1617 Sulfur in Kerosine 1988 Composition

1619 Sulfur in Residual Fuel Oil 1981 Composition

1625 Ciilfiir i^UIIUl ninvirlo I^IUAIUC PAVmoAtinn rV?! IIICCILIUII Tiiho lUMV? 1970 ^VIII|^V9l rkmnncition llVf 1 1630 TvAfo iidwc lUloffiii^ ivici^uiy inIII v«wcii aaI 1971 Composition

1633 Traf*o iidvc Fickinon'I'C ciciiiciiLs inIII ^aaI v>ucflB Plu " Acli 'y '^^1 1974 ^nmnocitinn ^UIII|JV9l LIUll 1634 '"^ Trace Elements in Fuel Oil 1978 Composition

1636 Lead in Reference Fuel (Gasoline) 1975 ^nmnocitinn ^Ulll|JU9l LIUll 1640 Trace Elements in Natural Water 1997 Composition

1641 ivitfiLUiy III WdLtfi 1974 ^nmnrhcitinn ^VIII|JW9l LI VII 1643 Trar*o iidw Flomontc cidiivjiiLa inIII lAfAtoi* wdLisi 1977 Composition

1645 ^ River Sediment 1978 Composition

1646 1982 Composition

1647 Prinritv Pnllutant PAHc 1981 Composition

1648 WTfJan rclrXICUIaXe IVIcitlcr 1978 r^nmnncition 1649 Urban Dust / Organics Composition

1650 Diesel Particulate Matter 1985 Composition

1659 Methane in Air 1976 Composition

1661 Sulfur Dioxide in Nitrogen 1976 Composition

1669 Propane in Air 1973 Composition

1677 Carbon Monoxide in Air 1974 Composition

1683 Nitric Oxide in Nitrogen 1974 Composition

1745 Indium Freezing Point 1998 Temperature

1761 Low Alloy Steel 1985 Composition

1866 Bulk Asbestos - Common 1988 Composition

1895 Nickel Microhardness - Knoop 1984 Hardness

26 Standard Reference Materials - The First Century
(Continuation of Table) Selected Key NBS/NIST Reference Materials Beyond the First 100 SS/SRM TITLE PATE APPLICATION

1896 Nickel IVIicrohardness - Vickers 1992 Hardness 1920 Near Infrared Reflectance Wavelength 1986 Wavelength

1921 Infrared Transmission Wavelength 1984 Wavelength

1922 Liquid Refractive Index - Mineral Oil 1999 Refractive Index 1930 Glass Filters for Spectrophotometry 1987 Transmittance

1941 Organics in Marine Sediment 1989 Composition

1945 Organics in Whale Blubber 1994 Composition

1951 Cholesterol in Human Serum (Frozen) 1988 Composition

I960 Nominal 10 Fm Dia. Polystyrene Spheres 1985 Length

1968 Gallium Melting Point 1977 Temperature

1974 Organics in Mussel Tissue 1990 Composition

2003 Aluminum on Glass - First Surface Mirror 1971 Reflectance 2030 Glass Filters for T^ansmittance 1976 Transmittance 2031 Metai-on-Quartz Filters Spectrophotometry 1984 Transmittance 2069 Scanning Electron Microscope Performance 1983 Efficiency 2071 Sinusoidal Roughness Specimen 1989 Roughness

2084 CMM Probe Performance 1994 Length

2092 Low-Energy Charpy V-Notch Test 1989 Energy

2109 Chromium (VI) Speciation Stan'rd Solution 1992 Composition

2121 Spectrometric Standard Solutions 1984 Composition

2135 Nickei/Cromium Thin-Film Depth Profile 1985 Length

2261 Chlorinated Pesticides in Hexane 1992 Composition

2287 Ethanol in Reference Gasoline 1995 Composition

2294 Reformulated Gasoline 1998 Composition

2381 Morphine 8i Codeine in Freeze-dried Urine 1992 Composition

2383 ' Baby Food Composite 1997 Composition

2390 DNA Profiling Standard 1992 Structure 2392 Mitochondrial DNA Sequencing - Human 1999 Structure 2415 Battery Lead 1991 Composition

2416 Bullet Lead 1988 Composition

2524 Optical Fiber Chromatic Dispersion 1997 Dispersion 2526 (111) p-Type Silicon Resistivity 1983 Resistance 2531 Etiipsometric Parameters - Si02 on Silicon 1992 Length

2541 Silicon Resistivity - 0.01 ohm • cm Level 1997 Resistance 2556 Used Auto Catalyst 1993 Composition

2567 Catalyst Package for Lubricant Oxidation 1992 Composition

2570 Lead Paint Film 1999 Composition

2583 ' Trace Elements in Indoor Dust 1998 Composition

2670 Toxic Metals in Freeze-dried Urine 1993 Composition

2676 Metals on Filter Media 1975 Composition

Standard Reference Materials - The First Century 27
(Continuation of Table) Selected Key NBS/NIST Reference Materials Beyond the First 100 SS/SRM TITLE DATE APPLICATION

2682 Sulfur in Coal 1982 Composition 2694 Simulated Rainwater 1985 Composition 2710 Montana Soil 1992 Composition

2712 Lead in Reference Fuel (Gasoline) 1988 Composition

2782 Industrial Sludge 1998 Composition

2810 Rockwell C Scale Hardness - Low Range 1998 Hardness

2811 Rockwell C Scale Hardness - Mid Range 1998 Hardness 2812 Rockwell C Scale Hardness - High Range 1998 Hardness 3087 Metal on Filter Media 1990 Composition

3101-69 Element Solution for Spectrometry 1986 Composition

3171 Multielement Mix A Standard Solution 1988 Composition

3190 Aqueous Electrolytic Conductivity 1990 Conductivity 3200 Magnetic Tape - Computer Amplitude 1969 Signal Amplitude 4200B Point Source Radioactivity 1965 Radioactivity 4201 Gamma Ray Niobium-94 1965 Radioactivity 4203B Cobalt-60 Gamma Ray Point Source 1967 Radioactivity 4350 Environmental Radioactivity - River Sediment 1975 Radioactivity 4351 Environmental Radioactivity - Human Lung 1982 Radioactivity 4352 Environmental Radioactivity - Human Liver 1982 Radioactivity 4353 Environmental Radioactivity - Rocky Flats Soil 1981 Radioactivity 4355 Environmental Radioactivity - Peruvian Soil 1982 Radioactivity 4356 Ashed Bone 2000 Radioactivity 4357 Environmental Radioactivity - Ocean Sediment 1997 Radioactivity 4408-27 Radiopharmaceuticals (Short Half Lives) 1960's Radioactivity

Standard Reference Materials - The First Century
Appendix C Past and Future Driving Forces on Reference

Material Production

The following table is the author's attempt

to crystalize the most powerful driving forces on the selection and production of reference

materials over the first century of NIST operation. On less stable ground, guesses are made at how new forces may develop over the course of the next century, thus shaping

the SRM program in years to come.

TIME FRAME

1901 - 1924

1925 - 1949

1950 - 1974

1975 - 2000

Speculation: 2001 - 2024

2025 - 2049

2050 - 2074

2075 - 2100

DRIVING FORCES

Automotive Age Explodes

Industrial Progress WW I Depression

Industrial Scale-up WW II Korea

Space Race Vietnam Human Needs

Info Age Explodes Economic Competition

Biotech Revolution

Infrastructure Reconstruction

New (Fusion?) Energy Age

Nanotechnology Breakthroughs

Large-scale Environmental

Reconstruction Space Colonization

SS/SRM RESPONSES

Metals, Ores, and Cement

Thermometry/Calorimetry

Sucrose Primary Chemicals

Glass and Ceramics Aluminum Alloys High Strength Alloys High Temperature Alloys Metrology & Semiconductor

Environmental & Clinical Food & Agriculture

Fuels, Oils & Engine Wear New Suite of DNA

Lab on Chip Validators Many SRMs become NTRMs

(NIST traceable reference materials) Ultrastrength Materials Nanometrology

Ultra Complex Natural Matrix Materials New Fuels, Foods, Materials

NIST's Numerically

Controlled Diamond Turning Machine used to manufacture RM 8240

Standard Bullets with identical sig- natures.

- : Materials - The