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Adjustment of a measuring systemfine & barks

Set of operations carried out on a measuring system so that it provides prescribed indications corresponding to given values of a quantity to be measured. (OIML V 1:2013)


Permission for a product or process to be marketed or used for stated purposes or under stated conditions. (OIML V 1:2013)


“systematic, independent, documented process for obtaining records, statements of fact or other relevant information and assessing them objectively to determine the extent to which specified requirements are fulfilled
Note: Whilst “audit” applies to management systems, “assessment” applies to conformity assessment bodies as well as more generally. (OIML V 1:2013)”

Accuracy class

Class of measuring instruments or measuring systems that meet stated metrological requirements that are intended to keep measurement errors or instrumental uncertainties within specified limits under specified operating conditions. (ISO/IEC GUIDE 99:2007)

Approved type

Definitive model or family of measuring instruments permitted for legal use, the decision being confirmed by the issuing of a type approval certificate. (OIML V 1:2013)

Conformity assessment

“Demonstration that specified requirements relating to a product, process, system, person or body are fulfilled.
Note 1: The subject field of conformity assessment includes activities defined in ISO/IEC 17000, such as testing, inspection and certification, as well as the accreditation of conformity assessment bodies.
Note 2: The expression “object of conformity assessment” or “object” is used in ISO/IEC 17000 to encompass any particular material, product, installation, process, system, person or body to which conformity assessment is applied. A service is covered by the definition of a product. (OIML V 1:2013)”


Operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication. (OIML V 1:2013)


“Third-party attestation related to products, processes, systems or persons
Note 1: Certification of a management system is sometimes also called registration.
Note 2: Certification is applicable to all objects of conformity assessment except for conformity assessment bodies themselves, to which accreditation is applicable. (OIML V 1:2013)”


Ability of the measuring instrument to maintain its performance characteristics over a period of use. (OIML V 1:2013)

Instrumental drift

Continuous or incremental change over time in indication, due to changes in metrological properties of a measuring instrument. (ISO/IEC GUIDE 99:2007)


Quantity value provided by a measuring instrument or a measuring system. (OIML V 1:2013)


Examination of a product design, product, process or installation and determination of its conformity with specific requirements or, on the basis of professional judgment, with general requirements. (OIML V 1:2013)

Initial verification

Verification of a measuring instrument which has not been verified previously. (OIML V 1:2013)

Initial verification of measuring instruments utilizing the manufacturer's quality management system

Manufacturer’s declaration of conformity of measuring instruments to legal metrological requirements for initial verification; the declaration is permitted on condition that the manufacturer has a quality management system implemented and approved by a competent body. (OIML V 1:2013)

International System of Units, SI

System of units, based on the International System of Quantities, their names and symbols, including a series of prefixes and their names and symbols, together with rules for their use, adopted by the General Conference on Weights and Measures (CGPM). (OIML V 1:2013)

Legally controlled measuring instrument

Measuring instrument required to conform to prescribed requirements, in particular legal metrological requirements. (OIML V 1:2013)

Legal metrology

“Practice and process of applying statutory and regulatory structure and enforcement to metrology.
Note 1 The scope of legal metrology may be different from country to country.
Note 2 Legal metrology includes
• setting up legal requirements,
• control / conformity assessment of regulated products and regulated activities,
• supervision of regulated products and of regulated activities, and
• providing the necessary infrastructure for the traceability of regulated measurements and measuring instruments to SI or national standards.
Note 3 There are also regulations outside the area of legal metrology pertaining to the accuracy and correctness of measurement methods. (OIML V 1:2013)”

Measurement error

Measured quantity value minus a reference quantity value. (ISO/IEC GUIDE 99:2007)

Maximum permissible error

Extreme value of the measurement error, with respect to a known reference value, supported by specifications or regulations for a given measurement, measuring instrument or measuring system. (OIML V 1:2013)

Measurement accuracy

Closeness of agreement between a measured quantity value and a true quantity value of a measurand. (ISO/IEC GUIDE 99:2007)

Measuring instrument

“Device used for making measurements, alone or in conjunction with one or more supplementary devices.
Note 1 A measuring instrument that can be used alone is a measuring system.
Note 2 A measuring instrument may be an indicating measuring instrument or a material measure. (OIML V 1:2013)”

Measurement uncertainty

Non-negative parameter characterizing the dispersion of the quantity values being attributed to a measurand, based on the information used. (ISO/IEC GUIDE 99:2007)


Affixing of one or more marks. (OIML V 1:2013)


Process of experimentally obtaining one or more quantity values that can reasonably be attributed to a quantity. (ISO/IEC GUIDE 99:2007)


Quantity intended to be measured. (ISO/IEC GUIDE 99:2007)


“Science of measurement and its application.
NOTE Metrology includes all theoretical and practical aspects of measurement, whatever the measurement uncertainty and field of application. (ISO/IEC GUIDE 99:2007)”

Measurement standard

Realization of the definition of a given quantity, with stated quantity value and associated measurement uncertainty, used as a reference. (ISO/IEC GUIDE 99:2007)

Metrological traceability

Property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty. (ISO/IEC GUIDE 99:2007)

Measurement repeatability

Measurement precision under a set of repeatability conditions of measurement. (ISO/IEC GUIDE 99:2007)

Measurement result

Set of quantity values being attributed to a measurand together with any other available relevant information. (ISO/IEC GUIDE 99:2007)

Measuring system

“Set of one or more measuring instruments and often other devices, including any reagent and supply, assembled and adapted to give information used to generate measured quantity values within specified intervals for quantities of specified kinds.
NOTE A measuring system may consist of only one measuring instrument. (ISO/IEC GUIDE 99:2007)”

Measurement unit

Real scalar quantity, defined and adopted by convention, with which any other quantity of the same kind can be compared to express the ratio of the two quantities as a number. (ISO/IEC GUIDE 99:2007)

Mandatory periodic verification

Subsequent verification of a measuring instrument, carried out periodically at specified intervals according to the procedure laid down by the regulations. (OIML V 1:2013)

Random measurement error

Component of measurement error that in replicate measurements varies in an unpredictable manner. (ISO/IEC GUIDE 99:2007)

Rejection mark

Mark applied to a measuring instrument in a conspicuous manner to indicate that the measuring instrument does not comply with the statutory requirements and that obliterates the previously applied verification mark. (OIML V 1:2013)


Smallest change in a quantity being measured that causes a perceptible change in the corresponding indication. (ISO/IEC GUIDE 99:2007)

Systematic measurement error

Component of measurement error that in replicate measurements remains constant or varies in a predictable manner. (ISO/IEC GUIDE 99:2007)

Stability of a measuring instrument

Property of a measuring instrument, whereby its metrological properties remain constant in time. (ISO/IEC GUIDE 99:2007)

Sealing mark

Mark intended to protect the measuring instrument against any unauthorized modification, readjustment, removal of parts, etc. (OIML V 1:2013)


“Means intended to protect the measuring instrument against any unauthorized modification, readjustment, removal of parts, software, etc.
Note This may be achieved by hardware, software or a combination of both. (OIML V 1:2013)”

Sensitivity of a measuring system

Quotient of the change in an indication of a measuring system and the corresponding change in a value of a quantity being measured. (ISO/IEC GUIDE 99:2007)

Type Approval

Decision of legal relevance, based on the review of the type evaluation report, that the type of a measuring instrument complies with the relevant statutory requirements and results in the issuance of the type approval certificate (OIML V 1:2013)

Type Approval Certificate

Document certifying that type approval has been granted. (OIML V 1:2013)


Determination of one or more characteristics of an object of conformity assessment, according to a procedure. (OIML V 1:2013)

Type approval mark

Mark applied to a measuring instrument certifying its conformity to the approved type. (OIML V 1:2013)


Digital device that has one or more keys (or mouse, touch-screen, etc.) to operate the instrument, and a display to provide the measurement results transmitted via the digital interface or an analog data processing device. (OIML V 1:2013)

Verification certificate

Document certifying that the verification of the measuring instrument was carried out and compliance with statutory requirements was confirmed

Verification Equipment

Equipment that meets the statutory requirements and that is used for verification. (OIML V 1:2013)

Verification mark

Mark applied to a measuring instrument in a conspicuous manner certifying that the verification of the measuring instrument was carried out and compliance with statutory requirements was confirmed. (OIML V 1:2013)


Verification, where the specified requirements are adequate for an intended use. (ISO/IEC GUIDE 99:2007)


Provision of objective evidence that a given item fulfils specified requirements. (ISO/IEC GUIDE 99:2007)

Verification of a measuring instrument

Conformity assessment procedure (other than type evaluation) which results in the affixing of a verification mark and/or issuing of a verification certificate. (OIML V 1:2013)