(V) Radio Tomographic Imaging for Metal Casting

Radio Tomographic Imaging (RTI) is a relatively new technique using simple measurements of radio signal strength to track differences of signal strength while objects move within a fixed area. This method uses an array of radios sending small packets of data. Using the differential pathloss between each of the radios a tomographic image can be created. The differential pathloss is a measure of the difference in the received signal strength indicator (RSSI) from baseline compared to the changing state that blocks the signal. Many of the applications of this technology include surveillance and monitoring changes within a visibly occluded space. This methodology lends itself nicely to observing the changes that occur within a sand cast as molten metal is poured into the cast. In this case, radios were used in a mono-planar orientation to measure the resolution and precision of this technology for this specific application. Future iterations of this technology may include using the radios in a three-dimensional orientation to measure not only a single slice, but image the entire cast as it fills the cavity.