ISO 18283:2022 石炭とコークス - 手動サンプリング | ページ 6

3.1

air-drying

process of bringing the moisture content of the sample near to equilibrium with the atmosphere in the area in which further reduction and division of the sample are to take place

Note 1 to entry: Air-drying to equilibrium with the atmosphere applies to coal. Drying of coke is generally to facilitate sample preparation.

3.2

bias

systematic error that leads to the average value of a series of results being persistently higher or persistently lower than those that are obtained using a reference sampling method

3.3

common sample

sample collected for more than one intended use

3.4

continuous sampling

taking of a sample from every consecutive sub-lot (3.30) so that increments (3.10) are taken at uniform intervals over the entire lot (3.11) being handled

3.5

cut

see increment (3.10)

3.6

divided increment

part obtained from the division of the increment (3.10) in order to decrease its mass

Note 1 to entry: Such division can be done with or without prior size reduction.

3.7

fixed-mass division

method of sample division in which the mass retained is predetermined and independent of the mass of the feed

3.8

fixed-ratio division

method of sample division in which the division ratio is predetermined, i.e. the mass of sample retained is a fixed proportion of the mass of the feed

3.9

general analysis test sample

sample prepared to pass a sieve of nominal size of openings of 212 µm used for the determination of most chemical and some physical characteristics

3.10

increment

portion of coal or coke extracted in a single operation of the sampling device

Note 1 to entry: Cut is an equivalent term.

3.11

lot

defined quantity of coal or coke for which the quality is to be determined

Note 1 to entry: A lot can be divided into sub-lots.

3.12

manual sampling

extraction of increments (3.10) by human effort

3.13

mass-basis sampling

taking of increments (3.10) whereby the position of each increment (3.10) to be extracted from the stream of coal or coke is measured by a mass interval of stream flow and the increment (3.10) mass is fixed

3.14

mechanical sampling

extraction of increments (3.10) by mechanical means

3.15

moisture sample

sample taken specifically for the purpose of determining total moisture

Note 1 to entry: For coke, this sample can also be used for general analysis.

3.16

nominal top size

aperture size of the smallest sieve in the range included in the R 20 Series on which not more than 5 % of the mass of the sample is retained

Note 1 to entry: See ISO 565, square hole.

3.17

physical sample

sample taken specifically for the determination of physical characteristics, e.g. physical strength indices or size distribution

3.18

precision

closeness of agreement between independent test results obtained under stipulated conditions

Note 1 to entry: This is often defined using an index of precision, such as 2 standard deviations.

Note 2 to entry: A determination might be made with great precision and the standard deviation of a number of determinations on the same sub-lot might, therefore, be low; but such results are accurate only if they are free from bias.

3.19

primary increment

increment (3.10) extracted at the first stage of sampling, prior to any sample division and/or sample reduction

3.20

random sampling

extracting of increments (3.10) at random mass or time intervals

3.21

replicate sampling

extracting, at intervals, of increments (3.10) that are combined in rotation into different containers to give two or more samples of approximately equal mass

3.22

representative sample

sample collected in such a manner that the analyses, size distribution and moisture content represent that of the lot (3.11)

3.23

sample

quantity of coal or coke, representative of a larger mass for which the quality is to be determined

3.24

sample division

process in sample preparation whereby the sample is divided into representative, separate portions

3.25

sample preparation

process of bringing samples to the condition required for analysis or testing

Note 1 to entry: Sample preparation covers mixing, particle size reduction, sample division and sometimes air-drying (3.1) of the sample and may be performed in several stages

3.26

sample reduction

process in sample preparation whereby the particle size of the sample is reduced by crushing or grinding

3.27

size analysis sample

sample taken specifically for particle size analysis

3.28

standard deviation

square root of the variance

3.29

stratified random sampling

extracting of an increment at random within the mass interval or time interval determined for mass-basis sampling or time-basis sampling respectively

3.30

sub-lot

part of a lot (3.11) for which a test result is required

3.31

systematic sampling

extracting of increments (3.11) at uniform time intervals according to a predetermined plan

3.32

test sample

sample which is prepared to meet the requirements of a specific test

3.33

time-basis sampling

extracting of increments whereby the position of each increment to be collected from the stream of coal or coke is measured by a time interval and the increment mass is proportional to the flow rate at the time the increment is taken

3.34

variance

measure of dispersion, which is the sum of the squared deviations of observations from their average divided by one less than the number of observations