BS EN 17539:2021 pdf free download – Modular mechanical locked floor coverings (MMF)一 Determination of geometrical characteristics.
8.1.6 Record the measured values for each test specimen to the nearest 0,01 mm.
8.2 Determination of length and width
Using the appropriate calliper gauge or any other equivalent tool, measure the length and the width of the surface layer along three lines parallel to the axis of the test specimen, two of these measurements approximately 20 mm from the perpendicular edges and the third equidistant from the first two.
8.3 Determination of straightness and squareness
8.3.1 Squareness
To measure the squareness q of floor covering panels by thickness gauge for each corner, place one edge of the long side of the panel against an arm of the L shaped steel device and slide it up so the short edge touches the other arm. Using the thickness gauges, determine the thickest gauge which can be easily inserted between the short side of the panel and the edge of the steel device. Repeat the procedure on the diagonally opposite corner (see Figure 3). Do not force the thickness gauges.
9.1 Thickness
Calculate the mean value of thickness from the number of measurements taken and express the result to 0,01 mm. If required by the specification, report the minimum and maximum measurements.
9.2 Length and width
Record all measured values and calculate the arithmetic mean value for length and for width to the nearest 0,1 mm for results up to 610 mm and to the nearest 0,2 mm for results over 610 mm.
9.3 Squareness
Report the greatest deviation at the end of the edge for squareness to the nearest 0,02 mm.
9.4 Straightness
Report the greatest deviation for each side of the panel at any point along the edge for straightness to the nearest 0,05 mm.
9.5 Flatness
9.5.1 Width flatness
Record all measured values and take the largest convex and concave values and divide each by the measurement d (see 8.4.1). Express the results to the nearest 0,01 %.
9.5.2 Length flatness
Record all measured valuesfi and take the largest convex and concave values and divide each by the nominal length of the specimen. Express the result to the nearest 0,01 %.
9.6 Openings and height differences
Calculate the mean value for the thirteen measurements of any openings between the panels and the mean value of the thirteen measurements of any height differences.
Record the maximum individual value and the mean value for both properties. Express the results in millimetres to the nearest 0,05 mm.
10 Precision statement
Inter laboratory tests are required to determine the precision of test methods in this document.
11 Test report
The test report shall contain the following information:
a) reference to this document and year of publication;
b) date the test was completed;
c) all details necessary for the identification of the specimens;
d) atmosphere for conditioning and testing.