Fig. 4. The measured dielectric constant from the coated part of CUP2 (K_ap) and CUP3 (K_ak), and from the uncoated part of CUP2 and CUP3 (K_u2 and K_u3) plotted against the water content during the upward infiltration experiments. The solid line represents the best-fit, third-order polynomial relationship between K_a and for the measurements at the lowest _a. CUP, coated–uncoated probe.