I&EC 152 |
| The utility of Time Domain Terahertz (TD-THz) methods for non-contact thickness measurements of wet and dry paint was investigated. The thickness is determined from the temporal difference between the reflections from the front and rear surface of the paint and the index of refraction. THz spectra of seven different marine paints were investigated. All paints studied exhibited sufficient transmissivity for the TD-THz thickness measurement approach to work. In order to demonstrate the utility of the approach, a tabletop apparatus generated thickness data for painted steel coupons. A model of the interaction between the THz pulse and the films provides good agreement with the experimental data. An investigation of the precision of the approach found a 120 nm 95% confidence interval when a 134 ìm film was measured. This method is not limited to paints, and is generally applicable to non-conductive films. |
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In Situ Spectroscopic Monitoring in Process Development and Production, Sponsored by Novel Chemistry with Industrial Applications Sub-Division
8:30 AM-12:00 PM, Wednesday, 13 September 2006 Moscone Center -- Room 252/254, Oral
Division of Industrial & Engineering Chemistry |