ISO 4593:1993 pdf download.Plastics一Film and sheeting一Determination of thickness by mechanical scanning
1 Scope
ISO 4593:1993 pdf download specifies a method for the determination of the thickness of a sample of plastics film or sheeting by mechanical scanning.
The method is not suitable for use with embossed film or sheeting.
2 Apparatus
2.1 Thickn.ss-m.suring device, capable of measuring to the following accuracies:
— up to and including 100 p.m to an accuracy of 1 p.m (see note 1);
— above 100 p.m and up to and including 250 p.m to an accuracy of 2 iim;
— above 250 .im to an accuracy of 3 p.m.
NOTE 1 Where the above is not adequate and a higher accuracy is required, this method should not be applied but a more suitable measuring device or method selected. The determination of gravimetric thickness is described in ISO 4591:1992, Plastics — Film and sheeting — Determination of average thickness of a sample, and average thickness and yield of a roll, by gravirnetric techniques (gravimetric thickness)
The measuring surfaces of the device shall comprise a plane lower face and either a plane or radiused upper face. All surfaces shall be polished.
2.1.1 In the case of planelplane measuring surfaces, the diameter of each face shall be between 2,5 mm and 10 mm and they shall be parallel to within 5 p.m. The lower face shall be capable of being adjusted to conform to this requirement. The force applied to the measuring face shall be 0,5 N to 1.0 N.
2.1.2 In the case of planelradiused measuring surfaces, the diameter of the plane lower surface shall not be less than 5 mm and the radius of curvature of the upper surface shall be 15 mm to 50 mm. The force applied to the radiused face shall be 0.1 N to
0,5 N.
NOTE 2 Transmission of the measured values may be performed, for example, mechanically (by micrometer), optically (by mirror instrument) or electronically (inductively).
3 Test specimens
Cut test specimens, about 100 mm wide, across the whole width of the sample. When required, take specimens at positions approximately 1 m apart in the longitudinal direction of the sample. The specimens shall contain no creases except those necessary for folding the film for presentation or packaging purposes. The specimens shall contain no other defects.
4 Procedure
4.1 Condition the specimens for at least 1 h at
23 C ± 2 C. For moisture-sensitive films, the conditioning time and atmosphere shall be as stated in the
specification for the material under test or as specified
between buyer and seller.
4.2 Ensure that the specimens and the faces of the measuring device (2.1) are free from contamination, for example dust.
4.3 Check the zero point of the measuring device before starting the measurements and recheck after each series of measurements.
4.4 When determining the thickness, lower the foot gentty to avoid deforming the material.ISO 4593 pdf download.