Onward and inward: extending the limits of thermographic NDE

Steven M. Shepard; James R. Lhota; Bruce A. Rubadeux; Tasdiq Ahmed

doi:10.1117/12.381551

30 March 2000 Onward and inward: extending the limits of thermographic NDE

Steven M. Shepard, James R. Lhota, Bruce A. Rubadeux, Tasdiq Ahmed

Proceedings Volume 4020, Thermosense XXII; (2000) https://doi.org/10.1117/12.381551
Event: AeroSense 2000, 2000, Orlando, FL, United States

Abstract

In current thermographic NDE practice, the detection limits of various methods are typically undefined, beyond citing the deepest flat bottom hole that has been successfully detected in a particular material. Little distinction is made between the ability of a thermographic system to detect the presence of a subsurface defect, to measure its physical properties, or to resolve adjacent defects. Although many practitioners rely on a `rule of thumb', which states that the aspect ratio (diameter/depth) of a detectable defect must be greater than 1, it has been shown to be unreliable as a basis for determining the feasibility of a particular inspection. It is possible to characterize the performance of a thermographic system using a simple procedure, so that the ability of the system to detect, resolve, or measure defects in a particular material or sample type can be successfully modeled. The intrinsic detection limits derived from this approach effectively defines a thermal point spread function that defines the minimum detectable defect size at a particular depth. This information can be used to remove blurring due to lateral heat flow, and extend the depth at which resolution is possible.

Citation Download Citation

Steven M. Shepard, James R. Lhota, Bruce A. Rubadeux, and Tasdiq Ahmed "Onward and inward: extending the limits of thermographic NDE", Proc. SPIE 4020, Thermosense XXII, (30 March 2000); https://doi.org/10.1117/12.381551

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available