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CHAPTER 11-NATIONAL BUREAU OF STANDARDS
DEPARTMENT OF COMMERCE
Barrels and other containers for lime.
SUBCHAPTER E-FELLOWSHIPS AND RESEARCH ASSOCIATES
Fellowships in laboratory standardization and testing for qualified citizens
of other American Republics. Research Associate Program.
SUBCHAPTER F-STANDARDS FOR SAFETY DEVICES
Standard for devices to permit the opening of household refrigerator doors
from the inside.
PART 200— POLICIES, SERVICES, (5) Advisory service to Government
agencies on scientific and technical prob
lems. Sec. 200.100 Statutory functions.
(6) Invention and development of de200.101 Measurement research.
vices to serve special needs of the Gov200.102 Standards for measurement.
ernment. 200.103 Types of calibration and test serv- (b) The calibration and testing activiices.
ties of the Bureau stem from the func200.104 Consulting and advisory services.
tions in paragraph (a) (1) and (3) of 200.105 Standard reference materials.
this section. These activities are as200.106 Critically evaluated data. 200.107 Publications.
signed primarily to the NBS Institute 200.108 Broadcasts.
for Basic Standards. Its program pro200.109 Request procedure.
vides the central basis within the United 200.110 Shipping, insurance, and risk of loss. States for a complete and consistent sys200.111 Priorities and time of completion. tem of physical measurement; coordi200.112 witnessing of operations.
nates that system and the measurement 200.113 Reports. 200.114 Use of results or reports.
system of other nations; and furnishes 200.115 Fees and bills.
essential services leading to accurate and 200.116 Description of services and list of
uniform physical measurements throughfees, incorporation by reference. out the Nation's scientific community, AUTHORITY: The provisions of this part
industry, and commerce. 200 are issued under sec. 9, 31 Stat. 1450, as
(c) The provision of standard referamended; 15 U.S.C. 277. Interprets or applies
ence materials for sale to the public is sec. 7, 70 Stat. 959; 15 U.S.C. 275a.
assigned to the Office of Standard ReferSOURCE: The provisions of this Part 200 ence Materials of the NBS Institute for appear at 32 F.R. 21012, Dec. 29, 1967, unless Materials Research. It evaluates the reotherwise noted.
quirements of science and industry for § 200.100 Statutory functions.
carefully characterized reference mate
rials, stimulates the Bureau's efforts to (a) The National Bureau of Stand
develop methods for production of needed ards has been assigned the following
reference materials and directs their functions (15 U.S.C. 271-278e):
production and distribution. For infor(1) The custody, maintenance, and
mation on standard reference materials development of the national standards of
see Subchapter B, Chapter II, of this measurement, and the provision of Title 15. means and methods for making measure
(d) The provision of technical seryments consistent with those standards,
ices to facilitate technical innovation and including the comparison of standards
industrial use of the results of modern used in scientific investigations, engi
science and technology is assigned to the neering, manufacturing, commerce, and NBS Institute for Applied Technology. educational institutions with the stand
The principal elements of the Institute ards adopted or recognized by the Gov
are (1) a Center for Computer Sciences ernment.
and Technology which conducts research (2) The determination of physical con
and provides technical services designed stants and properties of materials when
to improve cost effectiveness in the consuch data are of great importance to sci
duct of agency programs through the use entific or manufacturing interests and
of computers and related techniques; (2) are not to be obtained with sufficient ac
technical divisions which provide servcuracy elsewhere.
ices in technology of more general ap(3) The development of methods for
plicability; and (3) the Clearinghouse testing materials, mechanisms, and
for Federal Scientific and Technical Instructures, and the testing of materials,
formation which promotes widest effecsupplies, and equipment, including items
tive use by the scientific community, inpurchased for use of Government depart
dustry, and commerce of current informents and independent establishments.
mation in all fields of industrial tech(4) Cooperation with other govern
nology. mental agencies and with private organizations in the establishment of stand
$ 200.101 Measurement research. ard practices, incorporated in codes and (a) The NBS Institute for Basic specifications.
Standards carries out the Bureau's func
tions in developing an adequate national related to the SI units by agreed-upon system of physical measurement, and in conversion factors.
(b) The SI units for the six quantities providing related calibration services. Its staff continually reviews the advances in are defined as follows: science and the trends in technology, (1) In terms of a prototype object: examines the measurement potentiali- (1) Mass: The "kilogram” is the mass ties of newly discovered physical phe- of a platinum-irridium cylinder prenomena, and uses these to devise and im- served at the International Bureau of prove standards, measuring devices, and Weights and Measures in Sèvres, France. measurement techniques. As new re- Prototype No. 20 is kept at NBS; equivaquirements appear, there are continual lent prototypes are kept by other counshifts of program emphasis to meet the tries. most urgent needs for the measurement (2) In terms of natural phenomena: of additional quantities, extended (1) Length: The “meter" is the length ranges, or improved accuracies.
of exactly 1,650,763.73 wavelengths of (b) The basic research and develop- radiation in vacuum corresponding to the ment activities of NBS are primarily unperturbed transition between the funded by direct appropriations, and are levels 2p10 and 5d, of the atom of krypaimed at meeting broad general needs. ton 86, the orange-red line. The Bureau may also undertake investi- (ii) Time interval: The "second" was gations or developments to meet some long defined as 1/86400 of the time respecialized physical measurement prob- quired for an average complete rotation lem of another Government agency, in- of the earth on its axis with respect to dustrial group, or manufacturing firm, the sun. This, with daily corrections using funds supplied by the requesting from zenith transits of a star, is the organization.
basis for a universal time scale (UT),
With further correction for polar mo$ 200.102 Standards for measurement.
tion, it becomes UT1, and with further (a) An international treaty, the Met- correction for annual seasonal variaric Convention, was signed by 18 coun- tions, UT2. Also, the earth's average tries in 1875. In 1893 the United States daily rotation rate has been decreasing, established prototype No. 27 of the inter- thereby increasing the length of each national meter bar and prototype No. 20 year by about 6 ms over the length of the of the international kilogram as U.S. precejing year. Because of this, and Prototype Standards for length and other larger random fluctuations, the mass. Representatives of many of the universal second thus defined is not a 40 nations now adhering to this treaty constant. Consequently, the 11th Conmeet periodically, in the General Con- ference (1960) ratified the definition of a ference of Weights and Measures, to con- second based on ephemeris time (ET): sider detailed proposals concerning in- “the fraction 1/31,556,925.9747 of the ternational standards for physical meas- tropical year for January 0, 1900 at 12 urement. Successive Conferences have o'clock ephemeris time.” The 12th Connow agreed to adopt six units to serve ference (1964) authorized the designaas a practical base for an International tion of a cesium atom transition as a system of Units (Système International standard of frequency to be used temd'Unités, abbreviated SI)-kilogram, porarily for the physical measurement meter, second, kelvin, ampere, and can- of time. The 13th Conference (1967) dela. These are arbitrarily chosen but abrogated the 1960 action and decided precisely defined magnitudes of six phys- that: The unit of time of the Internaical quantities—mass, length, time, tem
tional System of Units is the second, deperature, electric current and luminous
fined in the following terms: "The secintensity, respectively_which are
ond is the duration of 9,192,631,770 pe
assigned unitary value in the International
riods of the radiation corresponding to System. Because the system is coherent,
the transition between the two hyperthe expressions for the other quantities
fine levels of the fundamental state of
the atom of cesium 133." of science and technology derived from
(iii) Temperature: The "kelvin,” the these six through the equations of unit of thermodynamic temperature, is physics will also have unitary coeffi- the fraction 1/273.16 of the thermodynacients. The units of the English system, mic temperature of the triple point of pound, inch, second, degree Fahrenheit, water. It was decided by the 13th Conetc. and of other systems of units are ference that the same name, kelvin, and
needia ; the
infor aterial of this
the symbol K should be used for expressing temperature intervals, dropping the former convention which expressed a temperature interval in degrees Kelvin or as abbreviated, deg K. However, the old designations are acceptable temporarily as alternatives to the new ones. One may also express temperature intervals in degrees Celsius.
(iv) Electric Current: The "ampere" is that constant current which if maintained in two straight parallel conductors of infinite length, of negligible circular sections, and placed 1 meter apart in a vacuum, would produce between these conductors a force equal to 2x 10-7 newton per meter of length.
(v) Luminous intensity: The “candela" is the luminous intensity, in the direction of the normal, of a blackbody surface 1/600,000 square meter in area, at the temperature of solidification of platinum under a pressure of 101,325 newtons per square meter.
(c) Although the six base units, and others derived from them, are exactly defined, their practical use requires a realization through the development of accurate measurement standards. Measurement standards may be based on physical phenomena, specimen objects, signal sources, or reference instruments. Extensive theoretical studies and laboratory experiments are involved in their selection, design, construction, and operation.
(d) It will be noted that a kilogram mass standard can be calibrated only through a series of comparisons, starting from the International Prototype. The units for the other five base quantities, and all quantities derived from them, are in principle independently realizable in many laboratories. In practice, however, inevitable minor differences among instruments, environments, and operators are bound to introduce small discrepancies. Periodic comparison of standards and the resolution of these discrepancies is required for compatibility among domestic standards laboratories, as well as internationally.
(e) within the United States, NBS consults with the major industrial and governmental standards laboratories, and cooperates with the Department of Defense and the National Conference of Standards Laboratories in conducting measurement agreement comparisons. Periodic inter-comparisons of NBS standards with those of other countries are made through the International Bu
reau of Weights and Measures, through international scientific organizations, or by direct arrangement. The operations of the International Bureau are supervised by the General Conference of Weights and Measures, to which U.S. delegates are appointed by the Department of State.
(f) Frequency and time comparisons within the United States are made by the National Bureau of Standards, the U.S. Naval Observatory, and other organizations which have an interest in precise time and frequency standards. The data from worldwide astronomical observations and from standards laboratories in many countries are coordinated by the International Bureau of the Hour, which announces recommended ap roximations for the rate difference between atomic and universal time, as well as for epoch adjustments. $ 200.103 Types of calibration and test
services. (a) NBS has developed instrumentation and techniques for realizing standards for the six base units of the International System of Units, as agreed upon by the General Conference of Weights and Measures. Reference standards have been established not only for these six base units, but also for many derived quantities and their multiples and submultiples. Such reference standards, or equivalent working standards, are used to calibrate laboratory and plant standards for other organizations. Accuracy is maintained by stability checks, by comparison with the standards of other national and international laboratories, and by the exploration of alternative techniques as a means of reducing possible systematic error.
(b) Calibrations for many types of instruments and ranges of physical quantities are described in the itemized service schedules of MP 250. On those services for which fees have been established, the fees are also listed in MP 250. In cases where fees have not been fixed, services will be billed on the basis of actual costs incurred. (See $ 200.116 for details relating to the description of service items and listing of fees.) Changes in services and fees are announced in supplements to MP 250 and in the monthly NBS Technical News Bulletin.1
1 For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.
(c) Special measurements not listed 20234). Those which perform testing are in MP 250 may be made upon request. listed in the ASTM Directory of Testing These might involve unusual physical Laboratories, Commercial and Instituquantities, upper or lower extremes of tional. (Directory available from the range, higher levels of accuracy, fast re- American Society for Testing and Masponse speeds, short durations, broader terials, 1916 Race St., Philadelphia, Pa. ranges of associated parameters, or spe- 19103.) Similar listings appear in buyer's cial environmental conditions. Such in- guides for commercial products and in quiries should describe clearly the meas- technical journals concerned with physurement desired. Indication of the ical measurement. scientific or economic basis for the re
$ 200.104 Consulting and advisory servquirement to be satisfied will be helpful
(a) In areas of its special competence, actual costs incurred.
the National Bureau of Standards offers (d) The principal emphasis of the Na
consulting and advisory services on varitional Bureau of Standards is on those
ous problems related to measurement, calibrations and other tests requiring
e.g. details of design and construction, such accuracy as can be obtained only by
operational aspects, unusual or extreme
conditions, methods of statistical condirect comparison with its standards. However, in order to maintain efficient
trol of the measurement process, autoutilization of specialized equipment and
mated acquisition of laboratory data, and
data reduction and analysis by computer. skilled personnel, NBS may when workload permits calibrate devices requiring
Brief consultation may be obtained at lesser accuracy but suitable for working
no charge; the fee for extended effort standards in plant or laboratory.
will be based upon actual costs incurred.
(b) To enhance the competence of (e) Other services which may be obtainable include:
standards laboratory personnel, NBS
conducts at irregular intervals several (1) Tests of measuring instruments to
group seminars on the precision measdetermine compliance with specifications or claims, when the evaluation is critical
urement of specific types of physical in national scientific or technical opera
quantities, offering the opportunity of tions, and when suitable facilities are not
laboratory observation and informal disavailable elsewhere.
cussion. A summer course in electromag
netic measurements and standards is (2) Referee tests in important cases when clients are unable to agree upon the
conducted periodically by the NBS Radio
Standards Laboratory at Boulder, Colomethod of measurement, the results of
Standard reference materials. writing to accept and abide by the find
Often the performance of a device or ings of NBS.
structure can be evaluated at the user's (f) NBS reserves the right to decline
laboratory by comparing its response to any request for services if the work unknown materials with its response to would interfere with other activities a standardized specimen or a substance deemed by the Director to be of greater of certified composition, properties, or importance. In general, measurement purity. Types of such specimens are listed services are not provided when widely in several of the detailed fee schedules in available from commercial laboratories, MP 250. For information regarding carenor for organizations or individuals in fully characterized materials see Subforeign countries.
chapter B of Chapter II of this Title 15. (g) Suggestions will be offered on The Office of Standard Reference Matemeasurement techniques and on other rials in the NBS Institute for Materials sources of assistance on calibration or Research administers a program to promeasurement problems when the Bu- vide many types of well-characterized reau's own equipment and personnel are materials that are needed to calibrate a unable to undertake the work. The Na- measurement system or to produce scientional Conference of Standards Labora- tific data that can be readily referred to tories issues a Directory of Standards
a common base.
$ 200.106 Critically evaluated data.
d sut Ids, i