| 摘要 |
<p>The present invention relates to a method and apparatus for measuring the presence of a fluid. One form of the present invention includes a substantially flat reflector (20) formed from a transparent material and having a flat side (26) and a ridged side (28). A beam of light shining through the flat side (26) is reflected back due to total internal reflection at the ridged surface (30) if the ridged side (28) is interfaced with a medium of substantially lower refractive index, such as air. A beam of light shining through the flat side (26) is not reflected if the ridged side (28) is interfaced with a medium of comparable refractive index, such as water. The reflector (20) may be interrogated by one or more remotely positioned optical detectors. <IMAGE></p> |
