NLST: United States Department of Commerce Technology Administration National Institute of Standard's and Measuring Devices

SPECIFICATIONS, TOLERANCES, United States Department of Commerce Technology Administration National Institute of Standards and Technology AND OTHER TECHNICAL REQUIREMENTS FOR WEIGHING AND MEASURING DEVICES as adopted by the 91st National Conference on Weights and Measures 2006 NIST Handbook 44 2007 Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices as adopted by the 91st National Conference on Weights and Measures 2006 Editors: Tina Butcher Linda Crown Lynn Sebring Richard Suiter Juana Williams National Institute of Standards and Technology Weights and Measures Division Gaithersburg, MD 20899-2600 U. S. Department of Commerce Carlos M. Gutierrez, Secretary Technology Administration Robert Cresanti, Under Secretary of Commerce for Technology National Institute of Standards and Technology William A. Jeffrey, Director NIST Handbook 44 2007 Edition Supersedes NIST Handbook 44, 2006 Edition Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately. Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the entities, materials, or equipment are necessarily the best available for the purpose. National Institute of Standards and Technology Handbook 44, 2007 Edition Natl. Inst. Stand. Technol. Handb. 44, 2005 Ed., 319 pages (Oct. 2006) CODEN: NIHAE2 U. S. GOVERNMENT PRINTING OFFICE WASHINGTON: 2006 For sale by the Superintendent of Documents, U. S. Government Printing Office Internet: bookstore.gpo.gov – Phone: toll free (866) 512-1800; DC area (202) 512-1800 – Fax: (202) 512-2550 Mail: Stop SSPO, Washington, DC 20402-0001 Handbook 44 - 2007 Foreword Handbook 44 was first published in 1949, having been preceded by similar handbooks of various designations and in several forms, beginning in 1918. Handbook 44 is published in its entirety each year following the Annual Meeting of the National Conference on Weights and Measures (NCWM). The Committee on Specifications and Tolerances of the NCWM developed the 2007 Edition with the assistance of the Weights and Measures Division (WMD) of the National Institute of Standards and Technology (NIST). This handbook includes amendments endorsed by the 91st National Conference on Weights and Measures during its Annual Meeting in 2006. NIST has a statutory responsibility for "cooperation with the states in securing uniformity of weights and measures laws and methods of inspection." In partial fulfillment of this responsibility, NIST is pleased to publish these recommendations of the NCWM. This handbook conforms to the concept of primary use of SI (metric) measurements recommended in the Omnibus Trade and Competitiveness Act of 1988 by citing SI units before inch-pound units where both units appear together and placing separate sections containing requirements in SI units before corresponding sections containing requirements in inch-pound units. In some cases, however, trade practice is currently restricted to the use of inch-pound units; therefore, some requirements in this handbook will continue to specify only inch-pound units until the NCWM achieves a broad consensus on the permitted SI units. In accord with NIST policy, the meter/liter spellings are used in this document. However, the metre/litre spellings are acceptable, and are preferred by the NCWM. It should be noted that a space has been inserted instead of commas in all numerical values greater than 9999 in this document, following a growing practice, originating in tabular work, to use spaces to separate large numbers into groups of three digits. This avoids conflict with the practice in many countries to use the comma as a decimal marker. iii Handbook 44 - 2007 Committee on Specifications and Tolerances of the 91st Conference Clark Cooney, OR Carol Fulmer, SC Todd R. Lucas,OH Bret Saum, CA Michael Sikula, NY Ted Kingsbury, Canada, Technical Advisor Juana Williams and Richard Suiter, NIST, Technical Advisors Past Chairmen of the Committee Conference 8-11 12-28 29-38 39-42 43-44 45-47 48 49-50 51-52 53 54-55 56-57 58 59 60 61 62 63 64 65 66 Chairman L.A. Fischer, NBS F.S. Holbrook, NBS J.P. McBride, MA R.E. Meek, IN J.E. Brenton, CA C.L. Jackson, WI T.C. Harris, VA R.E. Meek, IN G.L. Johnson, KY H.D. Robinson, ME R. Rebuffo, NE D.E. Konsoer, WI J.C. Mays, FL T.F. Brink, VT W.S. Watson, CA K.J. Simila, OR W.E. Czaia, MN M.L. Kinlaw, NC J.A. Bird, NJ D.A. Guensler, CA G.A. Delano, MT Conference 67 68 69 70 71-72 73 74 75 76 77-78 79 80 81 82-83 84 85 86 87 88 89 90 Chairman F.C. Nagele, MI L.H. DeGrange, MD S.A. Colbrook, IL D.A. Guensler, CA F. Gerk, NM K. Butcher, MD R. Andersen, NY D. Watson, TX J. Truex, OH C. Carroll, MA J. Jeffries, FL R. Suiter, NE G. West, NM R. Murdock, NC D. Brown, IA M. Hopper, CA G. Shefcheck, OR M. Coyne, MA R. Wotthlie, MD C. VanBuren, MI J. Kane, MT iv ... - tailieumienphi.vn