BS EN 17539 pdf free download

BS EN 17539-2021 pdf free download.Modular mechanical locked floor coverings (MMF)一 Determination of geometrical characteristics.
4.3 Squareness
To assess the squareness, each corner of a right-angled panel is fitted into the dihedral angle of a precision square and the maximum gap between the arm of the square and the ends of the panel is measured.
4.4 Straightness
To assess the straightness, the maximum opening between the panel and the straight edge is measured on the concave side using a suitable gauge.
4.5 Flatness
To assess width flatness the deviation in height is measured by direct contact with a dial gauge maintained at constant height. To assess length flatness the maximum opening between the panel and a straight edge is measured using a gauge.
4.6 Openings and height differences
A standard assembly is fixed together, openings of the assembled specimens are measured with thickness gauges and height differences are measured with callipers or depth gauges at standard predefined points.
5 Apparatus
5.1 Apparatus for thickness measurement
5.1.1 Movable circular upper plate.
For various types of floor covering panel structures, the diameter of the upper plate, the applied mass, the area and the pressure shall be in accordance with Table 1.
5.1.2 Fixed lower plate, at least equal to size of the upper plate and at least 15 cm2.
5.1.3 Dial gauge, to measure the distance between the plates with an uncertainty of measurement of
0,01 mm (0,1 mm over a range of 25 mm for textiles).
5.1.4 Straight edge, for example a ruler, for brushing the surface of textile specimens.
5.2 Apparatus for length and width measurement
A dial gauge, a sliding calliper gauge or equivalent device with a limit of permissible error of 0,05 mm for measurements up to 610mm and a limit of permissible of 0,1 mm for measurements over 610 mm.
5.3 Apparatus for squareness measurement
Flat bedplate apparatus, for measuring squareness of panels. This apparatus shall be an “Lu shaped steel device having an angle of 1,570 80 rad (90°) with a tolerance of ±0,000 18 rad (0,01°).
5.4 Apparatus for straightness measurement
5.4.1 Calibrated straight edge (steel ruler), of length at least equal to the length of the specimens, and having a maximum straightness deviation of 0,05 mm over 1 000 mm.
5.4.2 A set of thickness gauges.
5.5 Apparatus for determination of flatness
5.5.1 Apparatus for measuring width flatness, consisting of a dial gauge accurate to ±0,0 1 mm with a rounded tip of radius 5,5 mm, installed centrally in relation to three rounded supports with radii 5 mm. The supports shall be adjustable along a T-shaped assembly of bars to provide the required gauge length. The measurement, d, shall not be less than the width, of the test specimen minus 10 mm. The tip of the gauge in contact with the face of the test specimen shall apply a force of (1,0 ± 0,5) N. The mass of the apparatus shall not affect the flatness of the test specimen beyond the limit of permissible error of the gauge. The instrument shall be set to zero against a suitable flat reference plate (see Figure 1). For structured surfaces it is recommended to use rounded plates at the three rounded feet and a plate on the tip of the gauge, e.g. as described in 5J.J. and 8.1.2. Table 1.BS EN 17539 pdf download.