BS EN ISO 12951:2015 pdf free

BS EN ISO 12951:2015 pdf free.Textile floor coverings
The test apparatus shall be checked with a calibration carpet4) and calibrated by adjusting the number of to and fro transverse cycles set for that calibration carpet. This calibration covers the whole apparatus. If the calibration fails, the separate settings shall be checked.
The Tretrad machine shall be calibrated against the weight loss of the above mentioned calibration carpet. The number of cycles is adjusted to result in a weight loss that corresponds to the set weight loss of the calibration carpet (within a tolerance spread of ±7,5 %).
The tests shall be carried out at standard atmosphere (ISO 139). For conditioning, hang up the specimens singly or lay them out singly with the use-surface uppermost in the same atmosphere for at least 48 h.
Test specimens shall be conditioned twice, i.e. at the beginning and after the Tretrad test, before the weights of the specimens are taken. The conditioning, also after the test, is extremely important for the determination of the correct number of treads at the calibration.
Use a balance with an accuracy of 0,01 g.
Determine the exact area treated by the Tretrad machine. The stressed area is the product of the width of the Tretrad feet (5,5 cm) and the traverse length of the wheels. The traverse length is the measure from the stair edge in the front of the table to the opposite stop position of the wheels. Important: take for this measure the point below the wheel axis and calculate the average after a least 10 movements. The traverse length shall be between (80±2) cm. If not, correct the machine accordingly by changing the position of the metal strip for the contact switch.
The specimens are signed crossways with a line on one end on the pile side. Clamp the specimens always on the machine, in a way that the specimen-end with the line is next to the stair edge of the table.
The specimens have to be stretched again with the 20 kg weight of the machine after the first 500 cycles.
The vacuum cleaner of the machine shall work continuously. Ensure the nozzle is positioned symmetrically above the stressed area and always in contact with the specimen-surface. If not, provide the machine for a longer pair of plastic tubes.
Start the calibration at the first run with 2 000 cycles on the stop counter. If the average weight loss of the first two specimens is xxx g/m2±7,5 %, continue testing with another two calibration specimens for confirmation. If the first two results are not within this range, correct the number of cycles appropriately at the next tests.BS EN ISO 12951 pdf download.