5. New optical flow diagnostics methods

A.Yu. Zykov, N.A. Ivanova
Tyumen Industrial University, Russia, Tyumen, Tyumen State University, Russia, Tyumen

Photothermocapillary diagnostics method of sizes of the high conducting subsurface inclusions in the low conducting material

In this paper photothermocapillary (PTC) effect has been used for the diagnostics of the dimensions of the foreign subsurface high-conductive inclusions in a low conductive substrate. A modeling system was an ebonite disc with built-in flush vertical and horizontal copper plugs with diameter 2,2 mm. Maximum length of the vertical plug is lpl = 14 mm and horizontal – lpl = 52 mm. The working surface of the substrate was covered with a film of the dried black zapon lacquer absorbing the radiation of the pump laser beam (maximum Pe = 10,4 mW). A thin layer of silicone oil PMS-5 (h = 300 μm) was deposited on the working surface of the ebonite disc to generate of the PTC effect. Using a low-power probing unfocused laser beam we measured the diameter Dst of the stationary PTC signal in dependence on lpl. It was found that for the vertical plugs the method has a high sensitivity ΔDst/Δlpl = – 120 for lpl ≤ 1,6 mm, and for horizontal - maximum sensitivity ΔDst/Δlpl = – 79 is achieved for lpl ≤ 3 mm. Further increase in lpl does not lead to a noticeable change in Dst that is obviously associated with reaching a maximum of lpl that corresponds to a thermally semiinfinite plug. For case of the horizontal plugs an increase in Pe from 3,9 to 10,4 mW increases the slope ΔDst/Δx at the boundary in between ebonite and plugs for 9 times.
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