1、AMERICAN NATIONAL STANDARD for Calibration Systems AMERICAN SOCIETY FOR QUALITY CONTROL 611 EAST WISCONSIN AVENUE MILWAUKEE, WISCONSIN 53202 ASQC U1 b 0759506 0001803 003 W ANSVASQC MI -1 996 AMERICAN NATIONAL STANDARD for Calibration Systems Reaffirmation of ANSi/ASQC M1- 19871 Prepared by American
2、 Society for Quality Control Standards Committee for American National Standards Committee Z- I on Quality Assurance An American National Standard Approved on February 26, 1996 Abstract: This standard delineates the requirements for systems to calibrate measuring instruments to specific accuracies.
3、The requirements have been developed based on two alternate approaches of traditionally established practices or objec- tive measurement techniques. American National Standard: An American National Standard implies a consensus of those substantially concerned with its scope and provisions. An Americ
4、an National Standard is intended as a guide to aid the manufacturer, the consumer, and the general public. The existence of an American National Standard does not in any respect preclude anyone, whether he or she has approved the standard or not, from manufacturing, marketing, purchasing, or using p
5、roducts, processes, or pro- cedures not conforming to the standard. American National Standards are subject to periodic review, and users are cau- tioned to obtain the latest editions. Caution Notice: This American National Standard may be reviewed or withdrawn at any time. The procedures of the Ame
6、r- ican National Standard Institute require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of application. Purchasers of American National Standards may receive current information on all stan- dards by calling or writing the American Natio
7、nal Standards Institute. ASQC fl1 96 = 0759506 OOOL804 T4T = 01996 by ASQC Ail rights reserved. No part of this book may be reproduced in any form or by any means, electronic, mechanical, photo- copying, recording, or otherwise, without the prior written permission of the publisher. ASQC Mission: To
8、 facilitate continuous improvement and increase customer satisfaction by identifying, communicating, and promoting the use of quality principles, concepts, and technologies; and thereby be recognized throughout the world as the leading authority on, and champion for, quality. 10987654321 Frinted in
9、the United States of America Printed on acid-free paper Published by: ASQC 611 East Wisconsin Avenue Milwaukee, Wisconsin 53202 ASQC IL 96 = 0759506 OOOL805 986 ANSIJASQC M1- 1996 Contents Page 1 . Scope . 1 2 . Definitions 1 2.2 AcceptedStandard 1 2.3 Acceptedvalue 1 2.5 Accuracy Ratio 1 2.6 Calibr
10、ation . 1 2.8 CalibrationSystem 2 2.9 CheckStandard 2 2.10 Ensemble 2 2.11 Measuredvalue 2 2.1 References 1 2.4 Accuracy . 1 2.7 Calibration Ensemble 1 2.12 Measurement Assurance Method 2 2.13 Measuring Ensemble . 2 2.14 Measuring Insbument 2 2.16 Program Controls Method . 2.18 Reference Material 3
11、2.19 Reference Standard 3 2.2 1 Traceability . 3 2.15 Precision . 2 2 2.17 RandomError . 3 2.20 SystematicError . 3 2.22 Uncertainty . 3 3 . General 3 3.1 Intent . 3 3.2 Requirements 4 3.3 Consistency with ANSI 21.15 4 3.4 Selection of Method . 4 3.5 Use of Both Methods 4 3.6 Reference Materials . 4
12、 3.7 Reference Standards . 4 3.8 Maintenance of Ensembles 4 3.9 Traceability . 5 3.10 Specifications 5 3.11 AuditingCorrective Action 5 3.12 Out-of-Tolerance Notification . 5 3.13 Identification 5 3.14 Compliance . 5 3.15 External Organizations . 5 . 111 ASQC fil b = 075950b 0001806 812 ANSIIASQC M1
13、-1996 4 . Program Controls Method . 5 4.1 General 5 4.2 Calibration System Description . 5 4.3 Adequacy of Ensembles 6 4.4 EnvironmentalControls . 6 4.5 CalibrationIntervals . 6 4.6 Recallsystem . 6 4.7 Records 6 4.8 Traceability . 6 4.9 Calibration Procedures . 7 4.10 Identification of Calibration
14、Status . 7 5 . Measurement Assurance Method . 7 5.1 General 7 5.2 Calibration System Description 7 5.3 Adequacy of Ensembles 7 5.4 Monitoring . 8 5.6 Calibration Uncertainties 8 5.7 Traceability . 9 5.8 Documentation . 9 5.5 Frequency of Monitoring 8 Appendix: Quantifying Calibration Errors 1 . Intr
15、oduction: The Evaluation of Errors in a Calibration Process . 10 2 . Random Errors in a Calibration Process . 11 3 . Systematic Errors in the Calibration Process and Total Uncertainty . 12 4 . The Use of Control Charts and Check Standards in a Calibration Process 13 5 . Reference Standards in a cali
16、bration System 16 References 18 iv ASQC U1 96 m 0759506 0001807 759 m Foreword (This Foreword is not part of ANSUASQC M1-1996, American National Standard for Calibration Systems.) Providing services or manufacturing products of specified quality frequently requires the use of measuring instruments.
17、The calibration of such measuring instruments is required to assure their performance as intended. This standard delin- eates the requirements for systems to calibrate measuring instruments to specified accuracies. This document is a reaf- firmation of the 1987 version, ANSVASQC M1-1987. At the requ
18、est of many organizations and individuals concerned with quality control, production, or the providing of other services, the American Society for Quality Control (ASQC) decided in 1978 to embark on a project to develop a consensus standard for calibration systems and measurements. Under the auspice
19、s of the ASQC Metrology Techni- cal Committee, a Writing Group was formed in 1979 consisting of volunteers from a wide variety of industrial and governmental organizations to draft a Standard for Calibration Systems followed by a Standard of Measurements. The ASQC mandated that the standard be based
20、 on the “truth in measurements” principles paralleling the principles of quality control at the time of the drafting of this standard. It was recognized, however, that the large majority of exist- ing calibration systems operate under guidelines which may be described as “program controls.” Therefor
21、e, this stan- dard also includes, as one option for the potential user of the standard, the program controls method of operation of calibration organizations. The italicized Comments contained in this standard are explanatory material and are not considered to be part of this standard. The authors o
22、f the this standard are: Dr. Brian C. Belanger, US. Depment of Commerce, National Bureau of Standards, Chairman of the Technical Subgroup C. Bruce Coulter, U.S. Army TMDE Support Group, Chairman of the Editorial Subgroup Rolf B. E Schumacher, Rockwell International, Chairman of the Writing Group The
23、 authors are indebted to the numerous members of the Writing Group who have contributed to the standard their time, knowledge, effort, and experience. V ASQC ML 9b 0759506 OOOLBOB b95 ANSUASQC M1-1996 Calibration Systems 1. SCOPE This standard specifies general requirements for assuring the quality
24、of calibration in accordance with established practices or objective quality control techniques. This standard delineates the requirements for systems to cali- brate measuring instruments to specified accuracies; it is intended to cover only the operation of organizations en- gaged in the calibratio
25、n of measuring instruments, but not the application or control of the instruments they cali- brate, except for the measuring instruments each calibra- tion organization utilizes within its own operation. This standard, however, covers all calibrations the calibration organization performs. Control a
26、nd application of mea- suring instruments other than those utilized by calibration organization is the subject of a separate quality standard for measurements. This standard may be applied by any organization or part of an organization engaged in the per- formance of calibrations. Comments: The comm
27、ents are notpart of this standard and contain no requirements. They are provided for guidance and infor- mation purposes only. 2. DEFINITIONS 2.1 References The terms used in this standard conform to the definitions provided by the following documents: ANSVASQC Al, Dejnitions, Symbols, Formulas, and
28、 Tables for Control Charts (superceded in part by ANSV ISOIASQC A3534-1 and ANSJASOIASQC A3534-2). ANSVASQC A2, Tenns, Symbols and Definitions for Acceptance Sampling (superceded in part by ANSVIS01 ANSUASQC A3, Quality Systems Terminology (super- ceded by ANSJASOIASQC A8402). ASQC A3534-1 and ANSJA
29、SOIASQC A3534-2). 2.2 Accepted Standard An artifact or calibration ensemble embodying the ac- cepted value of a unit of measurement. 2.3 Accepted Value The value of an artifact or calibration ensemble expressed as a multiple of a unit of measurement. Accepted values are based upon in the following o
30、rder of priority: a. Legal values. Values defined and mandated by applic- b. Consensus values. Values defined by a consensus of c. Agreement values. Other values expressly agreed upon able law. users such as professional or trade organizations. by the affected parties of a calibration. Comments: Exa
31、mples of accepted values are as follows: a. Legal values. U.S. legal volt as maintained by the Na- tional Institute of Standards and Technology. Note that some legal values are dejned in terms of natural phys- ical constants, e.g., the meter b. Consensus values. Rockwell Hardness Standards. 2.4 Accu
32、racy The extent to which the measured value of a quantity agrees with the accepted value for that quantity. 2.5 Accuracy Ratio The ratio of the tolerance of the instrument being cali- brated to the uncertainty of the standard. 2.6 Calibration The comparison of an ensemble of unverified uncertainty t
33、o a calibration ensemble of quantified uncertainty to de- tect or correct any deviation from required performance specifications. 2.7 Calibration Ensemble An ensemble used to perform a calibration (see section 2.10). Comments: Calibration ensembles are controlled in accordance with this standard. 1
34、ASQC M1 b = 0757506 0001O 521 = ANSYASQC M1-1996 2.8 Calibration System uncertainties based on systematic observations of achieved results. Calibration uncertainty limits resulting from the application of Measurement Assurance Methods are considered estimates based upon objective verification of The
35、 management system of resources and responsibilities for equipment calibration. Comments: uncertainty components. Calibration system, ofren used synonymously with calibru- Comments: tion program, is an all-encompassing term to describe the management system whether applicable to the program controls
36、 method or measurement assurance method or combination of both. Measurement Assurance Methods are quality control methods that include the establishment and maintenance of a system of procedures intended to yield calibrations and meusurement with verijed limits of uncertainty bused on feedback of ac
37、hieved calibration or measurement re- sults. Achieved results are observed systematically and used to eliminate sources of unacceptable uncertainties. 2.13 Measuring Ensemble An ensemble used to perform measurement but not used in the process of calibration. 2.14 Measuring Instrument 2.9 Check Stand
38、ard A stable, well-characterized, in-house standard remea- sured periodically to ensure that the calibration process remains in a state of statistical control. 2.10 Ensemble The assemblage of instruments, artifacts, standards, per- sonnel, procedures, and associated equipment used to per- form a cal
39、ibration or make a measurement and all the in- fluences that affect the uncertainty of measurements or calibrations performed with this assemblage, except for the influence of the item under test and its variability. An instrument or assemblage of equipment only, cali- brated by the calibration syst
40、em but not used in the process of calibration. Comments: In order to understand the thrust of the standard, the reader must have an understanding of a nay concept, that of a mea- suring or calibration “ensemble.” he purpose of introduc- ing the term “ensemble” is to stress the fact that either of th
41、e two calibration control methods described in this standard must take into account all of the influences affecting the un- certainty of the calibration, eg., environment, procedures, personnel, etc. An example of a simple ensemble would be an ensemble for the calibration of gage blocks consisting o
42、f a standard gage block, a comparato an operator; environ- ment, and the calibration pmcedure. A more complicated ex- ample would be an automated resistance bridge interfaced Comments: Measuring ensembles and measuring instruments are only those ensembles and instruments used outside the calibra- ti
43、on system which serve to peg5orm a measurement, or em- body a unit of measurement in terms of length, mass, time, electric current, thermodynamic temperature, amount of substance, luminous intensity, or any combination or derivation of such units and such other units of measure- ment as are agreed u
44、pon by a calibration system and its customel: This definition includes goho-go devices. Measuring ensembles und instruments are not controlled in accordance with this standard and generally are not used in the calibration system. with a computer; the standard resisto the sofnyare control- ling the s
45、ystem, and other influences affecting the accuracy of this Set-up, such as ambient temperature. 2.11 Measured Value 2.15 Precision The degree of agreement among independent measure- ments of a quantity under specified conditions. The stated or recorded value after all appropriate adjust- ments and c
46、orrections, if any, have been incorporated into the observed value. 2.12 Measurement Assurance Method A method to determine calibration or measurement 2.16 Program Controls Method A method to limit calibration uncertainties based on con- trolling selected elements of the calibration system and the a
47、pplication of specified control methods. Calibration un- certainty limits resulting from the application of Program Controls Methods are considered estimates. 2 ASQC Ml 96 = 0759506 0002820 243 D ANSUASQC M1-1996 Comments: Program Controls Methods depend on the control of cali- bration system elemen
48、ts such as specijications, proce- dures, calibration intervals, equipment controls, etc., to ascertain that actually achieved uncertainties do not ma- terially exceed stated or intended uncertainties. 2.17 Random Error The limits of variation in measured value of unpre- dictable sign and magnitude o
49、ccurring when measure- ments of the same quantity are made under effectively identical conditions. 2.18 Reference Material A material or substance, one or more properties of which are sufficiently well established to be used for the calibration of a measuring ensemble or instrument, the assessment of a measurement method, or for assigning values to materials. Comments: Examples of reference materials are those used for the measurement of reflectance, coating thickness, radioactiv- ity, electrical resistivity, particle size, and viscositv. 2.19 Reference Standard An ensemble use
