ISO 11459:1997 鉄鉱石—認定された標準物質—化学分析で使用するための準備と認定 | ページ 6

3.1

iron ore

Any rock, mineral or aggregate of minerals, natural or processed, from which iron can be produced commercially.

3.2

reference material

rm

Material or substance one or more of whose property values are sufficiently homogeneous and well established to be used for the calibration of an apparatus, the assessment of a measurement method, or for assigning values to materials.

3.3

certified reference material

CRM

Reference material, accompanied by a certificate, one or more of whose property values are certified by a procedure which establishes its traceability to an accurate realization of the unit in which the property values are expressed, and for which each certificate value is accompanied by an uncertainty at a stated level of confidence.

3.4

certified reference material iron ore

A CRM prepared from an iron ore for the purpose of chemical analysis.

3.5

homogeneity

The condition of being of uniform structure or composition with respect to one or more specified properties. A reference material is said to be homogeneous with respect to a specified property if the property value, as determined by tests on samples of specific size, is found to lie within specific uncertainty limits, the samples being taken either from different supply units (bottles, packages, etc.) or from a single unit.

3.6

between-units variation

The variation of the mean characteristic value between units of material.

3.7

stability

The ability of a reference material, when stored under specified conditions, to maintain a stated property value for a specified length of time.

3.8

expiration date

A date, stated by the manufacturer and confirmed by the certifying authority, supplied together with a reference material, indicating the end of the period of validity of use of the reference material for reference purposes when it is stored under specified conditions.

3.9

sample

A representative quantity of material extracted from a batch of reference material.

3.10

test portion

The mass of material extracted from a unit of material for analysis.

3.11

within-unit

between-test-portions variation

The expected value of variation of the characteristic value between test portions taken from the same unit of material.

3.12

certified value (of a given quantity)

For a certified reference material, the value that appears in the certificate or other documentation accompanying the material, this value having been certified by a technically valid procedure.

3.13

uncertainty

That part of the expression of the result of a measurement that states the range of values within which the"true" value is estimated to lie within a stated probability.

3.14

accuracy

The closeness of agreement between the"true" value and the measured value.

3.15

best estimate (of the value of a given quantity)

An estimate of the value that is optimized by taking into account both metrological and technical judgement and statistical factors.

3.16

interlaboratory test

A series of measurements of one or more quantities performed independently by a number of laboratories on samples of a given material.

3.17

precision

The closeness of agreement between mutually independent test results obtained under prescribed conditions.

3.18

trueness (accuracy of the mean)

The closeness of agreement between the average value obtained from a large series of observations and an accepted reference value.

Note 1 to entry: The measure of trueness is usually expressed in terms of bias.

3.19

bias

The difference between the expectation of the observed values or test results and an accepted reference value.

3.20

reference method

A thoroughly investigated method, clearly and exactly describing the necessary conditions and procedures for the measurement of one or more property values, that has been shown to have trueness and precision commensurate with its intended use and that can therefore be used to assess the accuracy of other methods for the same measurement, particularly in permitting the characterization of an RM.

3.21

certification

The procedure for establishing, by technically valid operations, the measured values of one or more quantities of a material or substance. The procedure leads to the issuance of a certificate or equivalent documentation.

3.22

reference material certificate

A document certifying one or more property values for a certified reference material, stating that the necessary procedures have been carried out to establish their validity.

3.23

certification report

A document giving detailed information, supplementary to that contained in a certificate, on the methods of measurement used in obtaining the certified value(s) for a given reference material, and a summary of the results obtained (including a description of all factors affecting accuracy), and a description of the way the results were treated statistically.

3.24

certifying body

A technically competent body (organization or firm, public or private) that issues a reference material certificate.