« PreviousContinue »
CHAPTER 1-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 A-MEASUREMENT SERVICES
PART 200—POLICIES, SERVICES, (5) Advisory service to Government PROCEDURES, AND FEES
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 WWV-WWVH-WWVB 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 through
fees, 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 servments 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 suficient ac
technical divisions which provide serycuracy 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 system of physical measurement, and in providing related callbration services. Its staff continually reviews the advances in science and the trends in technology, examines the measurement potentialities of newly discovered physical phenomena, and uses these to devise and improve standards, measuring devices, and measurement techniques. As new requirements appear, there are continual shifts of program emphasis to meet the most urgent needs for the measurement of additional quantities, extended ranges, or improved accuracies.
(b) The basic research and development activities of NBS are primarily funded by direct appropriations, and are aimed at meeting broad general needs. The Bureau may also undertake investigations or developments to meet some specialized physical measurement problem of another Government agency, industrial group, or manufacturing firm, using funds supplied by the requesting organization. $ 200.102 Standards for measurement.
(a) An international treaty, the Metric Convention, was signed by 18 countries in 1875. In 1893 the United States established prototype No. 27 of the international meter bar and prototype No. 20 of the international kilogram as U.S. Prototype Standards for length and mass. Representatives of many of the 40 nations now adhering to this treaty meet periodically, in the General Conference of Weights and Measures, to consider detailed proposals concerning international standards for physical measurement. Successive Conferences have now agreed to adopt six units to serve as a practical base for an International system of Units (Système International d'Unités, abbreviated SI)—kilogram, meter, second, kelvin, ampere, and candela. These are arbitrarily chosen but precisely defined magnitudes of six physical quantities—mass, length, time, temperature, electric current and luminous intensity, respectively—which are assigned unitary value in the International System. Because the system is coherent, the expressions for the other quantities of science and technology derived from these six through the equations of physics will also have unitary coeficients. The units of the English system pound, inch, second, degree Fahrenheit, etc.—and of other systems of units are
related to the SI units by agreed-upon conversion factors.
(b) The SI units for the six quantities are defined as follows:
(1) In terms of a prototype object:
(i) Mass: The "kilogram" is the mass of a platinum-irridium cylinder preserved at the International Bureau of Weights and Measures in Sèvres, France, Prototype No. 20 is kept at NBS; equivalent prototypes are kept by other countries.
(2) In terms of natural phenomena:
(i) Length: The "meter" is the length of exactly 1,650,763.73 wavelengths of radiation in vacuum corresponding to the unperturbed transition between the levels 2p10 and 5ds of the atom of krypton 86, the orange-red line.
(ii) Time interval: The "second" was long defined as 1/86400 of the time required for an average complete rotation of the earth on its axis with respect to the sun. This, with daily corrections from zenith transits of a star, is the basis for a universal time scale (UT). With further correction for polar motion, it becomes UT1, and with further correction for annual seasonal variations, UT2. Also, the earth's average daily rotation rate has been decreasing, thereby increasing the length of each year by about 6 ms over the length of the preceding year. Because of this, and other larger random fluctuations, the universal second thus defined is not a constant. Consequently, the 11th Conference (1960) ratified the definition of a second based on ephemeris time (ET): "the fraction 1/31,556,925.9747 of the tropical year for January 0, 1900 at 12 o'clock ephemeris time.” The 12th Conference (1964) authorized the designation of a cesium atom transition as a standard of frequency to be used temporarily for the physical measurement of time. The 13th Conference (1967) abrogated the 1960 action and decided that: The unit of time of the International System of Units is the second, defined in the following terms: "The second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the fundamental state of the atom of cesium 133."
(iii) Temperature: The "kelvin," the unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water. It was decided by the 13th Conference that the same name, kelvin, and
the symbol K should be used for express reau of Weights and Measures, through ing temperature intervals, dropping the international scientific organizations, or former convention which expressed a by direct arrangement. The operations of temperature interval in degrees Kelvin the International Bureau are supervised or as abbreviated, deg K. However, the by the General Conference of Weights old designations are acceptable tempo- and Measures, to which U.S. delegates rarily as alternatives to the new ones. are appointed by the Department of One may also express temperature in State. tervals in degrees Celsius.
(f) Frequency and time comparisons (iv) Electric Current: The "ampere" within the United States are made by the is that constant current which if main National Bureau of Standards, the U.S. tained in two straight parallel con Naval Observatory, and other organizaductors of infinite length, of negligible tions which have an interest in precise circular sections, and placed 1 meter time and frequency standards. The data apart in a vacuum, would produce be from worldwide astronomical observatween these conductors a force equal to tions and from standards laboratories in 2x 10-7 newton per meter of length.
many countries are coordinated by the (v) Luminous intensity: The “can International Bureau of the Hour, which dela” is the luminous intensity, in the announces recommended approximations direction of the normal, of a blackbody for the rate difference between atomic surface 1/600,000 square meter in area, and universal time, as well as for epoch at the temperature of solidification of adjustments. platinum under a pressure of 101,325
$ 200.103 Types of calibration and test newtons per square meter. (c) Although the six base units, and
services. others derived from them, are exactly (a) NBS has developed instrumentadefined, their practical use requires a tion and techniques for realizing standrealization through the development of ards for the six base units of the Interaccurate measurement standards. Meas national System of Units, as agreed upon urement standards may be based on by the General Conference of Weights physical phenomena, specimen objects, and Measures. Reference standards have signal sources, or reference instruments. been established not only for these six Extensive theoretical studies and labora base units, but also for many derived tory experiments are involved in their quantities and their multiples and subselection, design, construction, and oper multiples. Such reference standards, or ation.
equivalent working standards, are used (d) It will be noted that a kilogram to calibrate laboratory and plant standmass standard can be calibrated only ards for other organizations. Accuracy is through a series of comparisons, starting maintained by stability checks, by comfrom the International Prototype. The parison with the standards of other naunits for the other five base quantities, tional and international laboratories, and all quantities derived from them, are and by the exploration of alternative in principle independently realizable in techniques as a means of reducing posmany laboratories. In practice, however, sible systematic error. inevitable minor differences among in (b) Calibrations for many types of instruments, environments, and operators struments and ranges of physical quantiare bound to introduce small discrepan ties are described in the itemized service cies. Periodic comparison of standards schedules of SP 250. On those services and the resolution of these discrepancies for which fees have been established, the is required for compatibility among fees are also listed in SP 250. In cases domestic standards laboratories, as well where fees have not been fixed, services as internationally.
will be billed on the basis of actual costs (e) Within the United States, NBS incurred. (See $ 200.116 for details reconsults with the major industrial and lating to the description of service items governmental standards laboratories, and listing of fees.) Changes in services and cooperates with the Department of and fees are announced in supplements Defense and the National Conference of to SP 250 and in the monthly NBS Standards Laboratories in conducting Technical News Bulletin.' measurement agreement comparisons. Periodic inter-comparisons of NBS
For sale by the Superintendent of Docustandards with those of other countries ments, U.S. Government Printing Office, are made through the International Bu- Washington, D.C. 20402.
(c) Special measurements not listed 20234). Those which perform testing are in SP 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- (f) NBS reserves the right to decline quirement to be satisfied will be helpful any request for services if the work would in determining future NBS programs. interfere with other activities deemed by Fees for work accepted will be based upon the Director to be of greater importance. actual costs incurred.
In general, measurement services are not (d) The principal emphasis of the Na provided when widely available from tional Bureau of Standards is on those commercial laboratories. calibrations and other tests requiring 132 F.R. 21012, Dec. 29, 1967, as amended at such accuracy as can be obtained only by 33 F.R. 10627, July 26, 1968; 38 FR 17493, direct comparison with its standards. July 2, 1973] However, in order to maintain eficient $ 200.104 Consulting and advisory sery. utilization of specialized equipment and
ices. skilled personnel, NBS may when workload permits calibrate devices requiring
(a) In areas of its special competence, lesser accuracy but suitable for working
the National Bureau of Standards offers
consulting and advisory services on varistandards in plant or laboratory. (e) Other services which may be ob
ous problems related to measurement, tainable include:
e.g. details of design and construction, (1) Tests of measuring instruments to
operational aspects, unusual or extreme determine compliance with specifications
conditions, methods of statistical con
trol of the measurement process, autoor claims, when the evaluation is critical in national scientific or technical opera
mated acquisition of laboratory data, and tions, and when suitable facilities are not
data reduction and analysis by computer. available elsewhere.
Brief consultation may be obtained at (2) Referee tests in important cases
no charge; the fee for extended effort when clients are unable to agree upon the
will be based upon actual costs incurred. method of measurement, the results of
(b) To enhance the competence of tests, or the interpretation of these re
standards laboratory personnel, NBS sults, but have agreed in advance in
conducts at irregular intervals several writing to accept and abide by the find
group seminars on the precision measings of NBS.
urement of specific types of physical (f) NBS reserves the right to decline
quantities, offering the opportunity of any request for services if the work
laboratory observation and informal diswould interfere with other activities
cussion. A summer course in electromagdeemed by the Director to be of greater
netic measurements and standards is importance. In general, measurement
conducted periodically by the NBS Radio services are not provided when widely
Standards Laboratory at Boulder, Coloavailable from commercial laboratories,
rado. nor for organizations or individuals in $ 200.105 Standard reference materials. foreign countries.
Often the performance of a device or (g) Suggestions will be offered on structure can be evaluated at the user's measurement techniques and on other laboratory by comparing its response to sources of assistance on calibration or
unknown materials with its response to measurement problems when the Bu
a standardized specimen or a substance reau's own equipment and personnel are of certified composition, properties, or unable to undertake the work. The Na- purity. Types of such specimens are listed tional Conference of Standards Labora in several of the detailed fee schedules in tories issues a Directory of Standards SP 250. For information regarding careLaboratories in the United States which fully characterized materials see Subperform calibration work (obtainable chapter B of Chapter II of this Title 15. from · NCSL Secretariat, c/o National The Office of Standard Reference MateBureau of Standards, Washington, D.C. rials in the NBS Institute for Materials