AS ISO 10545.8 pdf download

AS ISO 10545.8 pdf download.Ceramic tiles Method 8: Determination of linear thermal expansion
1  Scope
This part of ISO 10545 defines a test method for determining the coefficient of linear thermal expansion of ceramic tiles.
2  Principle
Determination of the linear thermal expansion coefficient for the temperature range from ambient temperature to 100 °C.
3  Apparatus
3.1 Suitable thermal expansion apparatus, capable of a rate of heating of (5 ± 1) °C/min with uniform distribution of heat. Certain types of apparatus require a soaking time at 100 °C. 3.2 Vernier calipers, or other suitable device. 3.3 Drying oven, capable of being operated at (110 ± 5) °C. Microwave, infrared or other drying systems may be used provided that it has been determined that equal results are obtained. 3.4 Desiccator
4  Test specimens
Cut two test specimens at right angles from the central portion of one tile so that their lengths are suitable for the apparatus. The ends of the test specimens shall be ground flat and parallel. If necessary, grind the test specimens so that the length of any side in cross-section is less than 6 mm and the area of cross-section is greater than 10 mm 2 . The minimum length of the test specimens should be 25 mm. In the case of glazed tiles, the glaze shall not be ground off the test specimens.
5  Procedure
It is necessary to make a previous calibration of the apparatus with a standard test specimen. The dimensions of the standard test specimen shall be the same as the dimensions of the test specimen. Dry the test specimens at (110 ± 5) °C until they reach constant mass, i.e. when the difference between two successive weightings at intervals of 24 h is less than 0,1 %. Allow them to cool in the desiccator (3.4) at ambient temperature. Using vernier calipers (3.2), determine the lengths to an accuracy of 0,002 times the length. Place a test specimen in the apparatus (3.1) and record the ambient temperature. Initially, and throughout the heating procedure, measure the length to an accuracy of 0,01 mm. Take temperature and length measurements at temperature intervals of no more than 15 °C. The rate of heating shall be (5 ± 1) °C/min.
6  Expression of results
The linear thermal expansion coefficient, α l , is expressed in 10 −6 per degree Celsius (10 −6 /°C), to the first decimal place, in accordance with the expression:
7  Test report
The test report shall specify the following:
a) reference to this part of ISO 10545, i.e. ISO 10545-8—;
b) a description of the tiles, including sample preparation;
c) the linear thermal expansion coefficient for both test specimens.