Since the advent of the laser, optical metrology has found a much wider use in engineering and is now providing engineers with previously unobtainiable data. The measurement of modal behaviour has traditionally been achieved through the use of accelerometers requiring some form of contact with the structure to be measured. There are however, cases where contact is neither possible or desirable. Laser techniques can provide both point and full-field vibration data remotely and at Gaydon Technology several forms of Doppler and holographic interferometer are utilised. This paper reports on the application of Electronic. Speckle Pattern Interferome try (ESPI), sometimes referred to as T.V. holography, to the analysis of engineering structures.ESPI allows dynamic and static analysis of structures to be undertaken remotely, full-field and in real-time by monitoring changes in the speckle field of a coherently illuminated object. The paper details why GTL has chosen an ESPI system, the basic principles and features of the GTL system and concludes by reviewing a number of applications.

Date Published: 26 August 1987
PDF: 7 pages
Proc. SPIE 0732, 1st Intl Conf on Vibration Control in Optics and Metrology, (26 August 1987); doi: 10.1117/12.937911

Published in SPIE Proceedings Vol. 0732:
1st Intl Conf on Vibration Control in Optics and Metrology
Lionel R. Baker; Daniel Vukobratovich, Editor(s)