ISO 4593:1993 download.Plastics – Film and sheeting Determination of thickness by mechanical scanning.
1 Scope
ISO 4593 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 Thlckn.ss-m.asurlng d.vic., cepeble of measuring to the following accuracies:
— up to and including 100 p.m to an accuracy of 1 pm (see note 1);
— above 100 p.m and up to and including 250 pm to an accuracy of 2 pm;
— above 250 pm to sri accuracy of 3 p.m.
NOTE 1 Wtere the above is not adequate end a higher accuracy is required, this method should not be applied but a more suitable measuring device or method selected. The detrmination of gravimetric thickness is described in ISO 4591:1992. PLasts’cs — Flfrn and stieeting — Determination of average thickness of a samp1e and average thickness and yed of a roil, by gcavrmetnc techniques grevimetric 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 planejplane measuring surfaces. the diameter of each face shall be between 2.5 mm and 10 mm and they shall be parallel to within 5 rim. 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 p4ane 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) Dl 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 Procedur.
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 end 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 gently to avoid deforming the material.
4.5 Determine the thickness of the specimens at points equally spaced along the length of the specimen, as follows:
a) for samples less than 300 mm wide — 10 points;
b) between 300 mm wide and 1 500 mm wide — 20 points;
c) more than 1 500 mm wide — minimum 30 points. Measurements shall not be taken within 50 mm of the edges of untrimmed rolls.
5 Precision
The precision of this test method is not known because interleboatory data are not available When interlaboratory data are obtained, a precision statement will be added at the following revision.
6 Test report
The test report shall include the following:
a) a reference to this International Standard;
b) all details necessary for identification of the sample;
c) the types of measunng face used end the force applied;
d) the length of the specimens;
e) the number of specimens measured;
f) the arithmetic mean of the individual measurements, to the nearest 1 pm or 0,001 mm, reported as the average mechanically measured thickness of the specimens; if required, the individual readings shall also be reported;
g) the total number of measurements made and, if required, the standard deviation.