Abstract: A TE0&ggr;&dgr; mode dielectric resonator (12) includes a cylindrical dielectric disk (32, 32′, 32″) having top and bottom ends (20, 22) spaced apart by a closed curve wall (24). The dielectric disk has an effective dielectric constant greater than 40. An axially aligned hole (36) is formed through the disk (32) between the top and bottom ends (20, 22). A conductive wall (34, 34″) is formed at or slightly beyond the wall (24) but does not cover the top and bottom ends (20, 22). The hole (36) has a preferred diameter between 0.21 and 0.4 times the diameter of the disk (32, 32′, 32″). The disk may be configured as a heterogeneous composite of dissimilar materials which exhibit increasing dielectric constant at increasing radial distance and increasing Q at decreasing radial distance.

Abstract: Ultrasonic apparatus determines the fluid depth, volume, and temperature in a storage tank. A system description for monitoring an underground storage tank containing gasoline is described. The system determines the water's and gasoline's depth, volume, and temperature. The apparatus consists of a remote console, ultrasonic probe, and interconnecting cable. The remote console contains a display to report tank information and a computer to operate the probe. The probe consists of an ultrasonic transducer above the bottom of the probe facing upwards to transmit and receive ultrasonic signals, vertically spaced reflectors and a temperature sensor to measure fluid temperature.