BS 2471:2005 pdf download

BS 2471:2005 pdf download.Textiles ——Woven fabrics ——Determination of mass per unit length and mass per unit area.
4 Apparatus
3.1 calibrated steel rule of length not less than 2 m. graduated in centimetres and millimetres.
NOTE The rule iheuId pre(rrabl hr 1 m In length.
4.2 Device to enable a specimen of full width to be cut at right angles to the selvedge.
4.3 Bulunce. capable of determining the mass of pieces or sample lengths (as relevant) to an accuracy ofO.2 %of the determrned mass.
4.4 Table, having a smooth flat surface, a width greater than that of the woven fabric to be measured and a length of not less than 4 m.
5 Atmosphere for conditioning and testing
The atmosphere for conditioning and testing textiles shall be in accordance with 115 EN ISO 139. Pre.conditioning shall be carried out as described in 115 EN ISO 139, unless it is known that the fabric, as received, can be conditioned from the “dry side”.
Equilibrium with the pre.conditioning or conditioning atmosphere shall be deemed to have been reached when the difference between successive weighings, made at intervals of not less than 2 h. does not exceed 0.5% of the final mass of the fabric when conditioned in this atmosphere.
6 Procedure
6.1 Sclvedges
If the mass per unit length (or area) of the selvedge differs appreciably from the mass per unit length (or area) of the fabric, the mass per unit area shall be determined on a sample from which the selvedges have been removed along the outermost warp threads of the body, and calculation(s) shall be based on the mass of the trimmed sample and its length and width.
6.2 Method 1: Measurement on short samples or cuttings that can be conditioned in the standard atmosphere for testing
6.2.1 Ensure that the fabric is cut across the full width of the piece along parallel lines at right angles to the aelvedge and that the length of the sample is not less than 0.5 rn and preferably 3 m to 4 m.
6.2.2 condition the sample or cutting in accordance with Clause 5.
6.2.3 Determine the conditioned length of the sample in accordance with BS EN 1773.
6.2.4 If the mass per unit area is required, determine the conditioned width of the sample in accordance with 115 EN 1773.
6.2.5 Determine the conditioned mass of the sample.
6.2.6 Calculate the mass per unit length in accordance with 7.2. or mass per unit area in accordance with 7.3. as required.
6.3 Method 2: Measurement on bulk pieces that can be conditioned in the standard atmosphere for testing
6.3.1 condition the whole piece in accordance with Clause 5.
6.3.2 I)etermine the conditioned length of the piece in accordance with 115 EN 1773.
6.3.3 If the mass per unit area is required, determine the conditioned width of the piece in accordance with BS EN 1773.
6.3.4 Determine the conditioned mass of the whole piece.
6.3.5 Calculate the mass per unit length in accordance with 7.2, or mass per unit area in accordance with 7.3. as required.
6.4 Method 3: Measurement on bulk pieces that cannot be conditioned In the standard
atmosphere for testing
6.4.1 Ensure that the whole piece is in the relaxed state in the ambient atmosphere.
6.4.2 Determine the length of the piece in the ambient atmosphere in accordance with BS EN 1773.
6.4.3 If the mass per unit area is required, determine the width of the piece in the ambient atmosphere in accordance with US EN 1773.
6.4.4 From preferably the middle of the piece, cut a full.width sample of length not less than I m and preferably 3 m to 4 m.
6.4.5 Determine the length of the sample in the ambient atmosphere in accordance with US EN 1773.
6.4.6 If the mass per Unit area is required, determine the width of the sample in the ambient atmosphere in accordance with US KN 1773.
6.4.7 Determine the mass of the whole piece, and also the mass of the sample at the same time, to minimize the effect of any sudden changes in the temperature or humidity of the ambient atmosphere,
6.4.8 Condition the sample in accordance with Clause 5.
6.4.9 Determine the conditioned length and mass of the sample and, if the mass per unit area is required. its conditioned width.
6.4.10 Calculate the conditioned length, width (if mass per unit area required) and mass of the whole piece in accordance with 7.1. Then calculate the mass per unit length in accordance with 7.2. or mass per unit area in accordance with 7.3. as required.
7 Calculation of results
7.1 Conditioned length, width (if mass per unit area is required) and mass (Method 3 only) For Method 3 only, first calculate the conditioned length, width (if mass per unit area required) and mass of the piece using equations 1 to 3.