The present invention provides a material that is cured to efficiently reflect light in the violet andor ultraviolet wavelength range emitted by optical elements such as LEDs. Vertices may be grouped to form primitives such as triangles, which are rasterized using two-dimensional arrays of samples bins. An analog to digital converter provides a digital output comprising a plurality of digital samples related to the sensed fluid voltage signal. A cross-sectional area of the predetermined section of the pipe is measured based on a measurement data including the radius of curvature and wall thickness at each of the plurality of positions of the outer peripheral surface of the predetermined section of the pipe.