ISO 1183-2:2019 pdf free
ISO 1183-2:2019 pdf free.Plastics一Methods for determining the density of non-cellular plastics
Conditioning and testing shall be in accordance with ISO 291 or the appropriate material standard. In general, conditioning specimens to constant temperature is not required, because the determination itself brings the specimen to the constant temperature of the test.
Specimens which change in density during the test to such an extent that the change is greater than the required accuracy of the density determination shall be conditioned prior to measurement in accordance with the applicable material specification. When changes in density with time or atmospheric conditions are the primary purpose of the measurements, the specimens shall be conditioned as described in the material specification and, if no material specification exists, then as agreed upon by the interested parties.
Specimens shall consist of pieces of the material cut to any convenient shape for ease of identification.The dimensions of each piece shall be chosen to permit accurate measurement of the position of the centre of the piece.
When cutting specimens from larger samples, care shall be taken to ensure that the characteristics of the material are not changed due to excessive heat generation. The surface of the specimen shall be smooth and free from cavities to minimize the entrapment of air bubbles upon immersion in the liquid,otherwise errors will be introduced.
Old specimens can be removed without destroying the gradient by collecting them in a wire screen basket attached to a long wire. The basket is pulled up very slowly from the bottom of the column and,after cleaning, returned to the bottom of the column. It is essential that this be done at a slow enough rate (approximately 10 mm length of column per minute) in order not to disturb the density gradient.It can conveniently be done using a clock motor. After cleaning the column, recheck the calibration and replot density versus height.ISO 1183-2 pdf free download.
