AS 1301.405:2021 – Methods of test for pulp and paper
AS 1301.405:2021 – Methods of test for pulp and paper.
For the determination of conditioned grammage, and oven-dry” grammage, the specimens shall be
conditioned in accordance with ISO 187.
For the determination of conditioned grammage, prepare and weigh the test pieces in the same atmospheric conditions as used to condition the specimens.
For the determination of conditioned grammage and oven dry (see A.1) grammage, using the cutting device (5.1). cut test pieces from conditioned specimens. If possible, cut at least 20 test pieces from at least five specimens, taking the same number from each specimen. For the determination of astaken grammage, follow the same procedure, niinimising the influence of the ambient atmosphere on the moisture content of the test pieces (see A.2).
Whenever possible, each test piece shall have an area of not less than 50 000 mm2 (preferably 200 mm * 250 mm) and not mare than 100 000 mm2, If necessary, It may be composed of several smaller pieces.
In cases where there Is only a limited sample area available and it is not possible to make up a test piece comprising several smaller pieces, a test area 01 not less than 10 000 mm2 (100 cm2) may be used. This shall be reported as a deviation from the preferred range of 50 000 mm2 to 100 000 mm2 specified in this document.
lithe variation in area of test pieces of the type of paper or hoard being tested exceeds the limits specified In 5.1. at the moisture content at which the grammage Is determined or if It Is unknown, determine the dimensions of each test piece to the nearest 0,5 mm and calculate the area of each.
Weigh each test piece on the balance (5.2) and express Its mass, or indicated gramniage If a special sheet-weighing balance is used (5.3), to three significant figures.
It Is recommended, especially when dealing with small pieces, that contact of the test piece with bare hands be avoided.
A.1 Determination of grammage on an “oven-dry” basis
IF necessary (see 5.1). determine the area of each test piece alter conditioning in accordance with Clause 7. Dry the test pieces in accordance with Iso 287 and determine their mass or gramniage (if a direct sheet-weighing balance is used). Calculate the grammage according to 9.1 or 9.2, as appropriate.
A.2 Determination of gram mage ‘as-taken”
This is based on the material in the condition pertaining at the time of sampling. Select specimens. cut test pieces and determine their mass or grammage (If a direct sheet-weighing balance is used) as quickly as the need for accuracy will allow. If the “as taken” grammage near the top of a reel is to be determined, cut the specimens out from a depth such that their moisture content has remained unaffected by the ambient atmosphere. Calculate the grammage according to 9.1 or 9.2, as appropriate.
The precision data presented in Tables 8.1 and 8.2 has been obtained from CEPI-CTS, the Comparative Testing Service of the Confederation of European Paper Industries. Estimates of repeatability and reproducibility from the CEPI-CTS programme are based on round-robin work in 2011 in which 17 laboratories from 11 European countries tested three different sample materials. The area of the test pieces used In the above testing service Is less than the preferred minimum of 50 000 mm2
The calculations have been made according to ISO/TR 24498111 and TAPPI T 1200121.
The repeatability standard deviation reported in Table B.1 is the pooled repeatability standard deviation; that is. the standard deviation is calculated as the root-mean-square of the standard dcv iations of the participating laboratories. This differs from the conventional definition of repeatability in ISO 5725-11l.
The repeatability and reproducibility limits reported are estimates of the maximum difference which should be expected in 19 out of 20 instances, when comparing two test results for material similar to those described under similar test conditions. These estimates may not be valid for different materials or different test conditions.
Repeatability and reproducibility limits are calculated by multiplying the repeatability and reproducibility standard deviations by 2,77.
NOTE 1 The repeatability standard deviation and the within-laboratory standard deviation are identical.
However, the reproducibility standard deviation Is NOT the same as the between-laboratory standard deviation.
The reproducibility standard deviation includes both the between-laboratory standard deviation and the within- laboratory standard deviation, viz.: