This work proposes the design of an off-axis null-screen that is displayed on an LCD screen and allows characterizing the surface quality of a sliding seismic isolator. For this purpose, we design a null-screen with a pattern of quasi-elliptical dots drawn on it, so that its image, which is formed by reflection on the concave surface, becomes a precise set of circular targets if the surface under test coincides with the designed surface. It is discussed how to integrate the off-axis measurement system to calibrate it by testing a reflecting concave surface, as a result optical parameters are obtained, at the surface vertex, such as radius of curvature, conic constant, and some deformation coefficients necessary for the characterization of the deformations associated to the test surface with respect to the design surface. Finally, based on the preliminary results, the advantages and disadvantages of the proposed test are discussed.
In the present work we present a novel approach of the null-screen test for testing a Parabolic Trough Solar Collector (PTSC) that involves the usage of custom designed dynamic patterns projected on a LCD display, in a new off-axis disposition that allows for more consistent retrieval of information as well as the ability to extract larger amounts of data in each test. We present images depicting an ongoing test that show clearly the advantages of this method compared to earlier versions of the null-screen test for the same collector.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
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.