677 KB40 KB199920252015Laloš, JernejMožina, JanezPožar, Tomažletnik:61številka:9str. 533-542, SI 98ISSN:0039-2480COBISSID:14173211URN:URN:NBN:SI:doc-O2MXFGMSenZveza strojnih inženirjev in tehnikov Slovenije et al.Strojniški vestnikabsolutna kalibracija senzorjaefekt apertureelastični valovi v ploščiGreenove funkcijelaserski pulzoptodinamikapiezoelektrični senzorHigh-frequency calibration of piezoelectric displacement sensors using elastic waves induced by light pressure|In the study of ultrasound propagation in matter, displacement sensors are indispensable and of these, the most sensitive are piezoelectric sensors. In order to eliminate the intrinsic effects of the sensor from the measurements, the sensor has to be properly calibrated, which means that its transfer function has to be evaluated from a known sensor input signal and a measured sensor output signal. This has usually been done by comparing the sensor response signal to a known input signal, namely, an ultrasonic waveform, which can be theoretically calculated using mathematical models and numerical algorithms. Until now, the point-source-point-sensor model has been primarily used, while ultrasonic waves were induced mechanically either by a dropped ball or a capillary fracture. In this paper, a real-source-real-sensor model is presented. It provides a more faithful waveform construction and it enables the removal of the aperture effect from the calculated sensor transfer function, thus giving correct and universal sensor response characteristics. This was corroborated by high-frequency calibration measurements of the output signal of a Glaser-type conical sensor in two positions on both surfaces of a glass plate, while ultrasonic waves were induced by the radiation pressure of a nanosecond laser pulseV prispevku je predstavljena kalibracija piezoelektričnega senzorja majhnih pomikov z ultrazvočnimi valovi, ki jih vzbudi svetlobni tlak laserskega bliska na površini steklene plošče. S primerjavo meritev in matematičnega modela širjenja ultrazvoka v trdni snovi je določena frekvenčna karakteristika senzorja pri višjih frekvencah kot doslej. Merjenje majhnih pomikov snovi je nepogrešljivo pri proučevanju širjenja mehanskega valovanja v snovi. Med vsemi senzorji so najbolj občutljivi tisti, ki delujejo z izkoriščanjem piezoelektričnega pojava, in so zato najbolj primerni za merjenje valovanj z majhno amplitudo pomika. Takšni senzorji so tako v uporabi v strojništvu, pri testiranjih ter v razvoju in raziskavah. Uporabljajo se pri meritvah akustične emisije in pri neporušnih preiskavah snovi, v mikroseizmologiji ter pri mnogih drugih aplikacijah ultrazvoka v snoviTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo