New Design of the Wideband High Sensitive Acoustic Emmision Sensors

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angličtina

The paper describes the construction of a wideband sensor to calibrate acoustic emission sensors via the reciprocal method according to NDIS 2109. The discussion is focused on the results obtained from the calibration of both a set of wideband sensors having a conical active element recommended by NIST and PINDUCER sensors with long damping rods and thin discs. Our special embodiment modifies the solution originally presented by [1], with various dimensions of the conical elements and the thin disc from piezoelectric ceramics. We analyze the impact exerted by the shape of the active element on the final parameters of the reference sensor. The sensors are tested by means of longitudinal and transverse calibration in a dedicated laboratory [2] and using a aluminium hemisphere [3] to enable the transverse calibration. The outcome of the research consists in a compact approach to yield the design and technological procedures for the manufacturing and measurement of acoustic emission sensors; the actual output of the calibration consists in the frequency characteristics of the sensor. The measured results are compared with those acquired via simulation based on the finite element method. [1] Y.–Ch. Lee, Z. Lin, Miniature piezoelectric conical transducer: Fabrication, evaluation and application, Ultrasonics, vol. 44, no. 1, 2006, DOI 10.1016/j.ultras.2006.05.197. [2] P. Benes, J. Fialka, Comparison of methods for absolute calibration of broadband AE sensors, EWGAE-ICAE2012, Granada, 2012. [3] P. Theobald, R. Pocklington, Velocity sensitivity calibration of AE sensors using the through wave method and laser interferometry, EWGAE 2010, Vienna, 2010.

acoustic emmision, sensor, wideband, calibration

FIALKA, J.; KREJČÍ, J.; BENEŠ, P.; HAVRÁNEK, Z.

29. 1. 2019

Fyzikální ústav AV ČR, v. v. i.

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