EN 30012-1:1993
(Main)Quality assurance requirements for measuring equipment - Part 1: Metrological confirmation system for measuring equipment (ISO 10012-1:1992)
Quality assurance requirements for measuring equipment - Part 1: Metrological confirmation system for measuring equipment (ISO 10012-1:1992)
Forderungen an die Qualitätssicherung für Meßmittel - Bestätigungssystem für Meßmittel (ISO 10012-1:1992)
Dieser Teil von ISO 10 012 enthält Forderungen an die Qualitätssicherung eines Lieferanten, um sicherzustellen, dass Messungen mit der beabsichtigten Genauigkeit erfolgen. Er enthält auch Anleitungen zur Umsetzung dieser Forderungen.
Exigences d'assurance de la qualité des équipements de mesure - Partie 1: Confirmation métrologique de l'équipement de mesure (ISO 10012-1:1992)
Zahteve zagotavljanja kakovosti za merilno opremo - 1. del: Sistem meroslovnega potrjevanja merilne opreme (ISO 10012-1:1992)
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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Zahteve zagotavljanja kakovosti za merilno opremo - 1. del: Sistem meroslovnega potrjevanja merilne opreme (ISO 10012-1:1992)Forderungen an die Qualitätssicherung für Meßmittel - Bestätigungssystem für Meßmittel (ISO 10012-1:1992)Exigences d'assurance de la qualité des équipements de mesure - Partie 1: Confirmation métrologique de l'équipement de mesure (ISO 10012-1:1992)Quality assurance requirements for measuring equipment - Part 1: Metrological confirmation system for measuring equipment (ISO 10012-1:1992)17.020Meroslovje in merjenje na splošnoMetrology and measurement in general03.120.10Vodenje in zagotavljanje kakovostiQuality management and quality assuranceICS:Ta slovenski standard je istoveten z:EN 30012-1:1993SIST EN 30012-1:1997en01-december-1997SIST EN 30012-1:1997SLOVENSKI
STANDARD
SIST EN 30012-1:1997
SIST EN 30012-1:1997
SIST EN 30012-1:1997
INTERNATIONAL STANDARD ISO 100124 Corrected First edition 1992-01-15 and reprinted 1993-05-01 Quality assurance requirements for measuring equipment - Part 1: Metrological confirmation System for measuring equipment Exigences d’assurance de Ia qua126 des gquipements de mesure - Partie 1: Confirmation m&rologique de Mquipement de mesure Reference number ISO 10012-1:1992(E) SIST EN 30012-1:1997
ISO mW2=1:1992(E) Contents Fage 1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~.~.~ 1 2 Normative references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*. 1 3 Def initions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 4 Requirements . . . . . . . .~.~.~.,. 4 4.1 General . . . . . . . . . . . . . . . . . . . . .~.,.,.~,.,. 4 4.2 Measuring equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*. 4 4.3 Confirmation System . .~.~~.~.~.~.~.~~.~. 4 4.4 Periodic audit and review of the confirmation System ,. 5 4.5 Planning . . . . . . . . . . . . . . . .*.~.,,,.,,,. 5 4.6 Uncertainty of measurement . . . . . . . .~.~~.~.~~.~~.~.~.~ 6 4.7 Documented confirmation procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.8 Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~. 6 4.9 Nonconforming measuring equipment . . . . . . . . . . . .*. 7 4.10 Confirmation labelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.11 lntervals of confirmation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~. 8 4.12 Sealing for integrity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4.13 Use of outside products and Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .o 9 4.14 Storage and handling .~.,,.,,~,~.,,,,,,,,.,,,.,,,.~. 9 4.15 Traceability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*. 9 4.16 Cumulative effect of uncertainties .,.,.,. 10 4.17 Environmental conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.18 Personne1 . . . . . . . . . . . . . .~.,,,.,,,,,,,,,.,,,.,,,.,,.,,.,,. 10 0 ISO 1992 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronie or mechanical, including photocopying and microfilm, without per- mission in writing from the publisher. International Organization for Standardization Case Postale 56 l CH-l 211 Geneve 20 l Switzerland Printed in Switzerland ii SIST EN 30012-1:1997
ISO 1ooXM:i992(E) Annexes A Guidelines for the determination of confirmation intervals for measuring equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 A.1 Introduction . . . . . . . . . . . . .*.~.~. 11 A.2 Initial choice of confirmation intervals D.OOODO.D.D*.O~.*~~~.*.~ 11 A.3 Methods of reviewing confirmation inten/als .,,.,.,.,.a 71 6 Bibliography ~.,.,,.,,.,.,.,.,.,.,. 14 . . . Ill SIST EN 30012-1:1997
ISO 10012=1:1992(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation sf national Standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Esch member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 10012-1 was prepared by Technical Committee lSO/TC 176, Quality management and quality assurance, Sub-Committee SC 3, Supporting technologies. ISO 10012 consists of the following Parts, under the general title Quality assurance requirements for measuring equipment: - Part 1: Metrological confirmation System for measuring equipment - Part 2: Measurement assurance Annex A is based on Organisation Internationale de Metrologie Legale (OIML) International Document No. 10, Guidelines for the determination of recalibration intervals of measuring equipment used in testing labora- tories. Annexes A and B of this part of ISO 10012 are for information only. iv SIST EN 30012-1:1997
ISO 1ooi2=1:1992(E) Introduction This part of ISO 10012 is written in the context of a Purchaser and a Supplier, both terms being interpreted in the broadest sense. The “Sup- plier” may be a manufacturer, an installer or a servicing organization re- sponsible for providing a product or a Service. The “Purchaser” may be a procurement authority or a customer using a product or Service. Suppliers become Purchasers when procuring supplies and Services from vendors or other outside sources. The subject of the negotiations relating to this part of ISO 10012 may be a design, an artefact, a product or a Service. This part of ISO 10012 may be applied, by agreement, to other situations. Reference to this part of ISO 10012 may be made: - by a Purchaser when specifying products or Services required; - by a Supplier when specifying products or Services offered; - by consumer or employee interests, or by legislative or regulatory bodies; - in assessment and audit of Iaboratories. This patt of ISO 10012 includes both requirements and (in clause 4) guidance on the implementation of the requirements. In Order to distinguish clearly between requirements and guidance, in clause 4 the latter appears in italic type-face, in a box, after each corre- sponding Paragraph under the heading “GUIDANCE”. The text under “GUIDANCE” is for Information only and contains no re- quirements. Statements given there are not to be construed as adding to, limiting or modifying any requirement. NOTE 1 Use of the masculine gender in this part of ISO 10012 is not meant to exclude the feminine gender where applied to persons. Similarly, use of the Singular does not exclude the Plural (and vice versa) when the sense allows. SIST EN 30012-1:1997
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INTERNATIONAL STANDARD ISO 10012=1:1992(E) Quality assurance requirements for measuring equipment - Part 1: Metrological confirmation System for measuring equipment 1 Scope 1.1 This part of ISO 10012 contains quality assur- ante requirements for a Supplier to ensure that measurements are made with the intended accuracy. lt also contains guidance on the implementation of the requirements. 1.2 This patt of ISO 10012 specifies the main fea- tures of the confirmation System to be used for a Supplier’s measuring equipment. 1.3 This part of ISO 10012 is applicable to measur- ing equipment used in the demonstration of com- pliance with a specification: it does not apply to other items of measuring equipment. This part of ISO 10012 does not deal extensively with other el- ements that may affect measurement results such as methods of measurement, competence of Personne1 etc.; these are dealt with more specifically in other International Standards, such as those referred to in 14 . . 1.4 This part of ISO 10012 is applicable: - to testing laboratories, including those providing a calibration Service; this includes laboratories oper- ating a quality System in accordance with lSO/IEC Guide 25; - to Suppliers of products or Services who operate a quality System in which measurement results are used to demonstrate compliance with specified requirements; this includes operating Systems that meet the requirements of ISO 9001, ISO 9002 and ISO 9003. The guidance given in ISO 9004 is also relevant; - to other organizations where measurement is used to demonstrate compliance with specified requirements. 1.5 The role of the Purchaser in monitoring a Sup- plier’s compliance with the requirements of this part of ISO 10012 may be fulfilled by a third Party, such as an accreditation or certification body. 2 Normative references The following Standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 10012. At the time of publication, the editions indicated were valid. All Standards are subject to revision, and Parties to agreements based on this part of ISO 10012 are encouraged to investi- gate the possibility of applying the most recent edi- tions of the Standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 8402:1986, Quality - Vocabulary. ISO 9001 :1987, Quality Systems - Model for quality assurance in design/development, production, instal- Ia tion and servicing. ISO 9002:1987, Quality Systems - Model for quality assurance in production and installation. ISO 9003: 1987, Quality Systems - Model for quality assurance in final inspection and test. ISO 9004: 1987, Quality management and quality sys- tem elements - Guidelines. SIST EN 30012-1:1997
ISO 10012=1:1992(E) ISO Guide 30:1981, Terms and definitions used in connection with reference materials. ISO/IEC Guide 251990, Genera/ requirements for the calibra tion and campe tence o f tes ting labora tories. BIPM/IEC/ISO/OI ML, International vocabulary of basic and general terms in metrology: 1984. value of the measurand or the indication of the measuring instrument. EXAMPLES ambient temperat measured voltage. [VIM, 2.101 3 Definitions For the purposes of this part of ISO 10012, the fol- lowing definitions apply. Most of them are based on the International vocabulary of basic and general terms in metrology (VIM): 1984, but they are not al- ways identical to the definitions given therein. Terms in ISO 8402 are also relevant. Relevant reference numbers are given in brackets following the defi- nitions. 3.1 metrological confirmation: Set of operations required to ensure that an item of measuring equip- ment is in a state of compliance with requirements for its intended use. NOTES 2 Metrological confirmation normally includes, Unter alia, calibration, any necessary adjustment or repair and sub- sequent recalibration, as weil as any required sealing and labelling. 3 For brevity, in this part of ISO 10012, this term is re- ferred to as “confirmation”. 3.2 measuring equipment: All of the measuring in- struments, measurement Standards, reference ma- terials, auxiliary apparatus and instructions that are necessary to carry out a measurement. This term in- cludes measuring equipment used in the course of testing and inspection, as well as that used in cali- bration. NOTE 4 In the context of this part of ISO 10012, the term “measuring equipment” is taken to encompass “measuring instruments” and “measurement Standards”. Moreover, a “reference material” is considered to be a type of “measurement Standard”. 3.3 measurement: The set of operations having the Object of determining the value of a quantity. [VIM, 2.011 3.4 measurand: A quantity subjected to measure- ment. NOTE 5 As appropriate, this may be quantity” or the “quantity to be measured” [VIM, 2.091 the “measured 3.5 influence quantity: A quantity which is not the subject of the measurement but which influences the ure; freq uency of an alternating 3.6 accuracy of measurement: The closeness of the agreement between the result of a measurement and the (conventional) true value of the measurand. NOTES 6 7 The use be avoided. “Accuracy” is a qualitative concept. of the term “precision,’ for “accuracy,’ should [VIM, 3.051 3.7 uncertainty of measurement: Result of the evaluation aimed at characterizing the range within which the true value of a measurand is estimated to lie, generally with a given Iikelihood. NOTE 8 Uncertainty of measurement comprises, in gen- eral, many components. Some of these components may be estimated on the basis of the statistical distribution of the results of series of measurements and tan be charac- terized by experimental Standard deviations. Estimates of other components tan only be based on experience or other information. [VIM, 3.091 3.8 (absolute) error of measurement: The result of a measurement minus the true value of the measurand. NOTES 9 See “true value (of a quantity)” and “conventional true value (of a quantity)” in VIM. 10 The term relates equally to - the indication, - the uncorrected result, - the corrected result. 11 The known Parts of the error of measurement may be compensated by applying appropriate corrections. The error of the corrected result tan only be characterized by an un- certainty. 12 “Absolute error”, which has a sign, should not be confused with ‘,absolute value of an error” which is the modulus of an error. [VIM, 3.101 2 SIST EN 30012-1:1997
ISO loo12-i:1992(E) 3.9 correction: The value which, added algebraically to the uncorrected result of a measurement, com- pensates for an assumed systematic error. NOTE 18 It is usual to consider stability with respect to time. Where stability with respect to another quantity is considered, this should be stated explicitly. [VIM, 5.161 13 The correction is equal to the assumed systematic er- 3.16 drift: The slow Variation with time of a rar, but of opposite sign. metrological characteristic of a measuring instrument. 14 Since the systematic error cannot be known exactly, the correction is subject to uncertainty. [VIM, 3.141 [VIM, 5.181 3.17 limits of permissible error (of a measuring instrument): The extreme values of an error permit- ted by specifications, regulations, etc. for a given 3.10 measuring instrument: A device intended to make a measurement, alone or in conjunction with supplementary equipment. measuring instrument. VIM, 5.231 [VIM, 4.01) 3.11 adjustment: The Operation intended to bring a measuring instrument into a state of Performance and freedom from bias suitable for its use. 3.18 (measurement) Standard: A material meas- ure, measuring instrument, reference material or sys- tem intended to define, realize, conserve or reproduce a unit or one or more values of a quantity in Order to transmit them to other measuring instruments by comparison. [VIM, 4.331 EXAMPLES 3.12 specified measuring range: The set of values for a measurand for which the error of a measuring Instrument is intended to lie within specified Iimits. a) 1 kg mass Standard; b) Standard gauge block; NOTES c) 100 a Standard resistor; 15 The upper and lower limits of the specified measuring range are sometimes called the “maximum capacity” and the “minimum capacity” respectively. d) Weston Standard cell; e) caesium atomic frequency Standard; 16 In some other fields of knowledge, “range” is used to mean the differente between the greatest and the smallest f) Solution of cortisol in human Serum as a Standard of concentration. values. [VIM, 5.041 [VIM, 6.011 3.13 reference conditions: Conditions of use for a measuring instrument prescribed for Performance testing, or to ensure valid intercomparison of results of measurements. 3.19 reference material: A material or substance one or more properties of which are sufficiently weil established to be used for the calibration of an appar- atus, the assessment of a measurement method, or for assigning values to materials. NOTE 17 The reference conditions generally specify “reference values” or “reference ranges” for the influence quantities affecting the measuring instrument. [VIM, 5.071 NOTE 19 This definition is taken from ISO Guide 30, where it has several notes. [VIM, 6.151 3.14 resolution (of an indicating device): A quan- titative expression of the ability of an indicating device to permit distinguishing meaningfully between im- mediately adjacent values of the quantity indicated. [VIM, 5.131 3.15 stability: The ability of a measuring instrument to maintain constant its metrological characteristics. 3.20 international (measurement) Standard: A Standard recognized by an international agreement to setze internationally as the basis for fixing the value of all other Standards of the quantity concerned. D/IM, 6.061 3.21 national (measurement) Standard: A stan- dard recognized by an official national decision to serve, in a countty, as the basis for fixing the value of all other Standards of the quantity concerned. SIST EN 30012-1:1997
ISO 10012=1:i992(E) NOTE 20 The national Standard in a country is often a “primary Standard”. [VIM, 6.071 3.22 traceability: The property of the result of a measurement whereby it tan be related to appropri- ate measurement Standards, generally international or national Standards, through an unbroken chain of comparisons. NOTES 21 The unbroken chain of comparisons is called a “traceability chain”. 22 (Applicable only to the French text.) [VIM, 6.121 3.23 calibration: The set of operations which es- tablish, under specified conditions, the relationship between values indicated by a measuring instrument or measuring System, or values represented by a material measure or a reference material, and the corresponding values of a quantity realized by a ref- erence Standard. NOTES 23 The result of a calibration permits the estimation of er- rors of indication of the measuring instrument, measuring System or material measure, or the assignment of values to marks on arbitrary scales. 24 A calibration may also determine other metrological properties. 25 The result of a calibration may be recorded in a docu- ment, sometimes called a “calibration certificate” or a “calibration report “. 26 The result of a calibration is sometimes expressed as a correction or a “calibration factor”, or as a “calibration curve”. [VIM, 6.131 3.24 (quality) audit: A systematic and independent examination to determine whether quality activities and related results comply with planned arrange- ments and whether these arrangements are im- plemented effectively and are suitable to achieve objectives. NOTE 27 The quality audit typically applies, but is not limited, to a quality System or elements thereof, to pro- cesses, to products, or to Services. Such audits are often called “quality System audit”, “process quality audit”, “product quality audit”, “Service quality audit”. [ISO 8402, 3.101 3.25 (quality System) review: A formal evaluation by top management of the Status and adequacy of the quality System in relation to quality policy and new objectives resulting from changing circumstances. [ISO 8402, 3.121 4 Requirements 4.1 General The Supplier shall document the methods used to implement the provisions of this patt of ISO 10012. This documentation shall be an integral part of the Supplier’s quality System. lt shall be specific in terms of which items of equipment are subject to the pro- visions of this part of ISO 10012, in terms of the allo- cation of responsibilities and in terms of the actions to be taken. The Supplier shall make objective evi- dence available to the Purchaser that the required ac- curacy is achieved. 4.2 Measuring equipment Measuring equipment shall have metrological charac- teristics as required for the intended use (for example accuracy, stability, range and resolution). Equipment and documentation shall be maintained so as to take account of any corrections, conditions of use (including environmental conditions), etc. that are necessary to achieve the required performante. The required Performance shall be documented. GUIDANCE The set of metrological characteristics (specific re- quirements) is an essential component of the con- firma tion sys tem. The Supplier is expected to include in his procedures a list of the specified re- quirements. Usual sources for such requirements include manufacturer’s litersture, regulations, etc. Wherever the sources are inadequate, the Supplier should himself determine the requirements. 4.3 Confirmation System The Supplier shall establish and maintain an effective documented System for the managing, confirmation and use of measuring equipment, including measure- ment Standards, used to demonstrate compliance with specified requirements. This System shall be designed to ensure that all such measuring equip- ment performs as intended. The System shall provide for the prevention 0% errors outside the specified lim- its of permissible error, by prompt detection of defi- ciencies and by timely action for their correction. 4 SIST EN 30012-1:1997
ISO 10012=1:1992(E) The confirmation System shall take full account of all relevant data, including that available from any statis- tical process control System operated by or for the Supplier. For each item of measuring equipment, the Supplier shall designate a competent member of his staff as authorized officer to ensure that confirmations are carried out in accordance with the System and that the equipment is in a satisfactory condition. In cases where any or all of a Supplier’s confirmation (including calibration) are replaced or supplemented by Services from outside sources, the Supplier shall ensure that these outside sources also comply with the requirements of this patt of ISO 10012 to the ex- tent necessary to ensure the Supplier’s compliance with the requirements. GUIDANCE The in tention of a confirmation s ystem is to ensure that the risk of measuring equipment producing results having unaccep table errors remains within acceptable bounds. The use of appropriate statis- tical methods for analysing the results of preceding calibrations, for assessing the results of cali- brations of several similar items of measuring equipmen t and for predicting cumula tive uncer- tainties is recommended. (See ISO 9004: 1987, 13.7.) The error attributable to calibration should be as small as possible. In most areas of measurement, it should be no more than one third and preferably one tenth o f the permissible error of the con firmed equipment when in use. lt is usual to carry out the calibration associated with an y con firma tion under re ference conditions, but where it is known tha t the Opera ting conditions are significantly different from the reference con- ditions, calibra tion under appropriate values o f the influence quantities ma y be carried out. Where this is impractical, due allowance should be made for the differente in the conditions. For a commercial device, it is usual to take the manufacturer’s claimed petiormance as the cri- terion of satisfactory Performance and accuracy. lt is sometimes necessary to modify the manufac- turer’s Claims. Where no manufacturer’s claimed Performance is available, criteria for sa tis factory Performance ma y have to be determined from experience. Some instruments, such as null detectors and co- incidence detectors, need periodic calibra tion and confirmation only in the restricted sense of func- tional checking to assure that they are functioning correctly. A very useful check that a measuring instrument continues to measure correctly is obtained by the use of a checking measurement Standard, applied to the instrument by the User. This will demon- strate if, at the value or values checked and under the conditions o f the check, the instrumen t is still functioning correctly. The checking measurement Standard itself needs to be calibrated and con- firmed and, in Order that the results obtained by its use tan with confidence be attributed to the in- strument and not to changes in the checking measurement Standard, it usually has to be simple and robust. The use of a checking measurement Standard is in no way a Substitute for regular cali- bration and confirmation of the instrument, but its use may prevent the use of an instrument which, within the intetval between two formal confir- mations, ceases to con form to specifica tion. 4.4 Periodic audit and review of the confirmation System The Supplier shall carry out, or shall arrange to be carried out, periodic and systematic quality auditing of the confirmation System in Order to ensure its continuing effective implementation and compliance with the requirements of this part of ISO 10012. Based on the results of the quality audits and of other relevant factors, such as feedback from Purchasers, the Supplier shall review and modify the System as necessafy. Plans and procedures for the quality audit and review shall be documented. The conduct of the quality audit and review and any subsequent corrective actions shall be recorded. 4.5 Planning The Supplier shal I other technical review any relevant Purchaser’s and requirements before commencing work on products or Services, and shall ensure that the measuring equipment (including measurement Standards) needed for the performante of the work are available and are of the accuracy, stability, range and resolution appropriate for the intended applica- tion. SIST EN 30012-1:1997
ISO 10012~1:1992(E) GUIDANCE This review should be carried out at as early a Stage as practical, so as to permit comprehensive and effective planning of the Supplier’s confir- mation System. 4.6 Uncertainty of measurement In performing measurements and in stating and mak- ing use of the results, the Supplier shall take into ac- count all significant identified uncertainties in the measurement process including those that are attrib- utable to measuring equipment (including measure- ment Standards) and those contributed by personnel procedures and environment. In estimating the uncertainties, the Supplier shall take account of all relevant data including that available from any statistical process control System operated by or for the Supplier. GUIDANCE When it has been demonstra ted by a calibra tion tha t measuring equipmen t is performing correctly (in accordance with its specification), it is usual to assume that the errors produced while the equip- ment is in use do not exceed its specified limits o f permissible error. This is assumed to hold until the equipment is next calibra ted and con firmed. This may not be true under the often more arduous conditions o f use as compared with the controlled conditions of the calibration. It may therefore be expedient to compensate for this by tightening the product acceptance limits. The amount of this tigh tening depends on the particular circums tances and is a matter for judgement based on experi- ence. (See 4.17.) The use of statistical methods is recommended to monitor and control measurement uncertainty on a continuing basis. (See ISO 9004: 1987, 13.1.) 47 . Documented confirmation procedures The Supplier shall designate and use documented procedures for all confirmations performed. The Supplier shall ensure that all procedures are ad- equate for their purpose. In particular, procedures shall contain sufficient information to ensure their proper implementation, to ensure consistency of ap- plication from one application to another, and to en- Sure valid measurement results. The procedures shall be available, as necessary, to staff involved in performing confirmations. GUIDANCE Procedures may be, but are not necessarily, limited to the compilation of published Standard measure- ment practices and a Purchaser’s or an instrument manufacturer’s written instructions. The amount of detail in procedures should be commensurate with the complexity of the confirmation process. These methods ma y be elaborated using the tech- niques of sta tis tical process con trol, whereb y measurement Standards and measuring instru- ments are intercompared in-house, drifts and faults are determined, and any necessary corrective ac- tion is taken. Sta tistical process con trol is comple- mentary to regular calibra tion and rein forces con fidence in measurement results during the in- tervals between confirmations. 4.8 Records The Supplier shall maintain records of the make, type and serial number (or other identification) of all rele- vant measuring equipment (incuding measurement Standards). These records shall d
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