AS 1301.457:2020 pdf free.Methods of test for pulp and paper Method 457: Determination of moisture content in paper, board and pulps.
5 Apparatus
5.1 Balance
A balance having an accuracy of 0.05 % of the mass to be weighed, or better.
5.2 Containers
Containers for preventing changes in moisture content during the transporting and weighing of test pieces, having airtight lids or other equivalent means of sealing, and made from a lightweight material not subject to change under conditions of drying specified in this document. Where test pieces are taken according to AS/NZS 1301.417s, the containers need to be large enough to contain sheets without cutting or tearing them. Before using a container, determine its tare weight.
5.3 Drying oven
A drying oven capable of being maintained at an air temperature of 105 ± 2 °C in the usable volume and having forced ventilation.
5.4 Desiccator
A dessicator equipped with freshly dried desiccant.
6 Sampling
Take a sample which is representative of the paper, board or pulp the moisture content of which is to be determined.
Two standard sampling procedures for determining the moisture content of a lot exist, although any alternative procedure may be followed
NOTE When the purpose is to obtain test pieces from a lot of paper or board, AS/NZS 1301.417s may be followed. When the purpose is to obtain test pieces from a lot of pulp in bale or roll form, AS/NZS Iso 7213 may be followed.
Throughout the chosen sampling procedure, minimize the chance of the sampled material losing or gaining moisture in exchange with the ambient air by wrapping the sample. Avoid moisture gain of the sampled material from contact with the skin by wearing gloves.
Take sufficient sample material to ensure that the mass of moisture in a test piece can be determined to within 0.05 % of the mass of the test piece and so that additional test pieces can be obtained to permit the performance of replicate measurements if required. Enclose each test piece in a tared dry container (see Clause 5.2).
7 Procedure
7.1 Weighing of test piece
If the test piece is hot when taken, allow to cool and equalize the air pressures inside and outside the container by momentarily opening and reclosing the lid immediately before weighing. Weigh the test piece in its container.AS 1301.457 pdf download.