Abstract: The disclosed technology can be used in the development and operation of multistatic probes that can characterize substances and relationships between substances. A multistatic probe can include transmitting and receiving conductive elements that are electrically distinct and which are capable of conveying electromagnetic energy to/from a substance of interest. The transmitting and receiving conductive elements can be arranged to be in contact with at least one dielectric mismatch boundary between substances of interest, whereby an electromagnetic signal transmitted on the transmitting conductive element causes a corresponding electromagnetic signal to be coupled to the receiving conductive element in response to the transmitted signal being in proximity to the dielectric mismatch boundary.

Abstract: A level monitoring system for a floating roof tank is provided. The level monitoring system includes a switch electrically connected to a monitor. When the tank reaches a high fill level, the switch closes an electrical circuit. The monitor senses that the circuit has become closed, indicating the high fill level, and sends a signal to an alarm module. The level monitoring system may use either a cable pull switch or a tilt switch that are activated by the floating roof of the tank when the a predetermined level has been reached.

Abstract: A method and apparatus are provided for monitoring a liquid level in a closed tank with a differential pressure sensor module disposed in a bottom portion of the tank, by routing a pressure reference tube extending from the pressure sensor module through the interior of the tank and attaching an opposite, open, vented end of the pressure reference tube to the tank at a point inside of the tank in an upper portion of the tank.