Inhalt
accreditation
calibration
certified reference materials (CRMs)
interlaboratory comparisons
internal quality control
precision
proficiency test
accreditation
Procedure by which an authoritative body formal recognition that a body or a person
is competent to carry out specific tasks Note Accreditation does not of itself qualify
the laboratory to approve any particular product. However, accreditation may be
relevant to approval and certification authorities when they decide whether or not
to accept data produced by a given laboratory in connection with their own activities
EN 45003
calibration
The set of operations that establish, under specified conditions, the relationship
between values of a quantity indicated by a measuring instrument or measuring system,
or values represented by a material measure or a reference material, and the corresponding
values realised by standards Note
- The result of a calibration permits either the assignment of values of measurands
to the indications or the determination of corrections with respect to indications.
- A calibration may also determine other metrological properties such as the effect
of influence quantities.
- The result of a calibration may be recorded in a document, sometimes called a calibration
certificate or a calibration report.
International vocabulary of basic and general terms of metrology 1993/ 6.11
certified reference materials (CRMs)
Reference material, accompanied by a certificate, one or more of whose property
values are certified by a procedure which establishes traceability to an accurate
realisation of the unit in which the property values are expressed, and for which
each certified value is accompanied by an uncertainty at a stated level of confidence.
Notes
- The definition of a "reference material certificate" is given in ISO Guide 30/4.2
- CRMs are generally prepared in batches for which the property values are determined
within stated uncertainty limits by measurement on samples representative of the
whole batch
- The certified properties of certified reference materials are sometimes conveniently
and reliably realised when the material is incorporated into a specially fabricated
device, e.g. a substance of known triple-point into a triple-point cell, a glass
of known optical density into a transmission filter, spheres of uniform particle
size mounted on a microscope slide. Such devices may also be considered as CRMs.
- All CRMs lie within the definition of "measurement standards" or "etalons" given
in the "International vocabulary of basic and general terms of metrology 1984 (VIM)".
- Some RMs and CRMs have properties which, because they cannot be correlated with
an established chemical structure or of other reasons, cannot be determined by exactly
defined physical and chemical measurement methods. Such materials include certain
biological materials such as vaccines to which an International unit has been assigned
by the World Health Organisation.
International vocabulary of basic and general terms of metrology 1993/ 6.14
interlaboratory comparisons
Organisation, performance and evaluation of tests on the same or similar test items
by two or more laboratories in accordance with predetermined conditions
ISO/IEC Guide 43
internal quality control
The application of proficiency tests within the scope of the appraisal of test laboratories
to the accreditation according to DIN EN ISO / IEC 17025:2000 in this norm as means
for the protection of the quality of test and calibration results. At the moment
in the field of “mechanical-technological tests” proficiency tests were offered
only on a small scale. There are no elaborated programs to pursue the quality of
the generated test achievement continuously and to be able to show where necessary
an improvement of the test quality. IfEP guarantees the professional conception
and realisation of bilateral and multilateral proficiency tests. The assessment
of the lab results occurs on the base of certificated authoritative values or the
average values ascertained during the proficiency tests of the participants. In
the proficiency tests carried out by the IfEP have taken part each time more than
100 laboratories from more than 25 european countries.
precision
closeness of agreement between independent test results obtained under prescribed
(stipulated) conditions ISO 3534-1
proficiency test
Determination of
laboratory testing performance by means of interlaboratory test comparisons Ermittlung