EN 326-1-1994 pdf download.Wood-based panels — Sampling, cutting and inspection — Part 1: Sampling and cutting of test pieces and expression of test results.
4 Definitions
For the purpose of this standard, the following definitions apply:
Drawn at random:
Sampling of panels in such a way that each panel of the inspection lot has an equal chance of being selected, and cutting of test pieces from a single panel in such a way that each jiarl of the panel ha.s an equal chatice of lwing selected as a test piece. Inspection lot
A proportion of production, which is presented at a gven time for sam)hng and mspe(’ti(lfl. consisting of panels of the same type within the ‘anu’ thickness range and coming from the same prodUCtion line.
Inspection lot size:
Number of panels in one in.sl)eetu)n tot. Quality characteristic:
A property that is essential for the judgenwnt of a product in accordance with a relevant 1N sped fleat ion.
Sample
A collection of panels which are drawn from an msl)ection lot. t’nles.s otherwise agreed, the parwls of the sample are drawn at random.
Measurement:
Tin’ value of a specific quality (hara(terIs( w obtained either from a test piece or from i (tired measurement.
Test piece:
A piece of panel cut to the size required for testing
a SIWCIIK l)fl)IWJ1Y.
1%t ValUC
The value of a pcdfie quahy characteristic obtained from a test piece.
Variable:
A tesi value or measurement which can he measured on a continuous scale.
5 Sampling
5.1 Sampling of panels
The size of the sample n depends on the purpose of the determination of panel prnpertles. l)etailed information on the size of the sample for quality control in the factory is given in EN 32f-2, and for the inspection of the performance of a consignmeiit of panels in EN 326-3. Alternatvely, the sample site may be specified in the relevant E specification.
5.2 Sampling of test pieces
Due io the variability both within and between panels. it is necessary to test a certain number of panels ,g as well as a certain number of test pieces m. cut from a single ii’anel. in order to obtain reliable results.
Examples of the nurtiniuru mimlwr of test pieces in are given in table 1. for other panel properties ni shall be as laid down in the relevant EN for the respective test method.
For the determination of those properties which (bffc’r in the IWo priiwipal directions of the plane of the panel. two groups of m test pieces shall he cut from each panel. One group shall have its hnguudinal axAs parallel to the direction of the pnxluction (or the Length of the panel), the ot her shall have its longitudinal axis Ierlwn(li(Ular to this direct lOt).
In testing the linding qua! I y ol ply W( ( )d. relates to a pair of glue hues and to each pretreatnient (see annex A).
6.1 The test pieces shall be cut from the individual paneLs to the dimensions specified in the relevant standards of test methods, using a suitable method to ensure unbiased selection. At least one test piece of each group of test pieces shall be cut from the edge of the trimmed panel after any edge profiling andior protective treatment has been removed.
6.2 An example of a cutting plan for small test pieces is given in figure 1. Except for plywood bonding quality tests, for which a cutting plan is given in annex A, the minimum distance between two test pieces for the same test shall be 100 mm. This requirement may be waived if replacement test pieces are required.
6.3 All test pieces cut from a panel shall be marked on the same surface with:
– the test panel identification number:
– the test piece serial number;
– and if possible, the original length direction
and the original upper or lower surface of the
panel.
6.4 For panels which are asymmetric about the centre of their thickness, so that the test result is influenced by which surface is uppermost when tested (e.g bending strength), half of the total number of test pieces in (i.e. rn 2) shall be tested in each surface orientation.
In all other cases where the onentat ion of the surface of the panel is of minor influence on the property tested, the position of the upper or lower surface during the test shall be chosen at random.EN 326-1-1994 pdf download.