BS ISO 17859:2015 pdf download – Fine ceramics (advanced ceramics, advanced technical ceramics) — Measurement method of piezoelectric strain at high electric field

BS ISO 17859:2015 pdf download – Fine ceramics (advanced ceramics, advanced technical ceramics) — Measurement method of piezoelectric strain at high electric field 4 Measuring environment The measurement should be carried out in an environment free from acoustic noise and vibrations. It is desirable to control the measurement temperature 25 ± 5 °C and relative humidity less than 60 %. 5 Specimens 5.1 General The test specimen shall be of any ceramics that can be cut into desired shapes such as disks and quadrilateral plates. There is no limit in specimen size and shape, if the specimen is held horizontally with a small tilt. 5.2 Shape and size Specimens are made by cutting out from ceramics or single crystals. The shape of the specimen should be disk or quadrilateral plate, with smooth surfaces. Thickness distribution less than ± 1 % is desirable within the plate. The standard dimensions of the specimen are 0,3 mm – 1,0 mm in thickness, 5 mm – 15 mm in size, and 15 – 25 in the ratio of size to thickness. A desirable example of such disc is 0,5 mm in thickness and 10 mm in diameter. 5.3 Electrodes Electrodes should be deposited on both sides of the specimen plate, leaving the edge region free. This edge region should have an area of less than 10 % of the sample surface. The electrode is desirable with tough adhesion and without deterioration. An example of such electrode metal is Au, Ag and Pt. 5.4 Polarization The specimen should be treated by a poling procedure. Polarized direction should be shown on the specimen surface. Typically the positive side of the sample is marked with a dot or cross. 6 Principle The strain of the specimen is induced by the piezoelectric effect when an electric field is applied between the two electrodes of the specimen. The strain is detected as the thickness variation of the specimen using a displacement meter. The strain vs. E-field curve is drawn, and the piezoelectric constant is calculated from this curve. 7 Measurement equipment 7.1 Equipment Figure 1 shows an example of a system block diagram for piezoelectric strain measurement. 7.2 Components of equipment 7.2.1 Signal generator. A function generator is recommended to generate the triangular waveform with the frequency range of 0,1 Hz to 1 Hz. Figure 2 shows an example of an applied waveform. 7.2.2 Power source. A power source...