EFFECTS OF THERMAL AND ELECTRICAL PROPERTIES OF THIN METAL FILM IN PHOTOINDUCTIVE FIELD-MAPPING TECHNIQUE FOR EDDY-CURRENT PROBES

Autor: Cheng-Chi Tai, Yen-Lin Pan
Rok vydání: 2011
Předmět:
Zdroj: Progress In Electromagnetics Research B. 31:189-203
ISSN: 1937-6472
DOI: 10.2528/pierb11050302
Popis: Photoinductive (PI) fleld mapping for eddy-current (EC) probes above a thin metal fllm was performed by multiphysics analysis with two-dimensional flnite element method (FEM). The FEM model of PI method was used to observe how metal fllm properties afiect the fleld-mapping signals of EC probes. The PI signal was tested for efiects of resistivity, temperature coe-cient of the resistivity, thermal conductivity, heat capacity, and thin fllm density The applicability of actual thin fllm materials for mapping the fleld of EC probe when using PI method was discussed. Field-mapping signals of EC probe coils with tilt angles of 0 - , 5 - , 10 - , 15 - , and 20 - were also examined with appropriate metal fllm material. These experiments showed that the higher-resolution fleld-mapping signals of EC probes can be obtained by given a titanium thin fllm The resolution of fleld-mapping signals of EC probes correlated positively with resistivity, heat capacity, and density of thin fllm and correlated negatively with its thermal conductivity. Improved understanding of distinct fleld distribution of EC probes enables selection of optimal probes for EC inspection.
Databáze: OpenAIRE