American Society for Testing and Materials (ASTM). Current edition approved December 1, 2011. Published March 2012. Originally approved in 1993. Last previous edition approved in 2006 as E 1353 – 00 (2006). 1 p. This test method covers the determination of the noise equivalent temperature difference (NETD; NE[delta]T) of thermal imaging systems of the conventional forward-looking infrared (FLIR) or other types that utilize an optical-mechanical scanner; it does not include charge-coupled devices or pyroelectric vidicons.