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 method of determining a temperature and a pressure in a tank is provided. The method comprises the steps of obtaining sensor data and calculating coefficients. Then, a bridge resistance is ratiometrically determined from a bridge voltage. A temperature is calculated with the coefficients and the bridge resistance. Thereafter, a transition from a temperature measurement mode to a pressure measurement mode is made. A voltage per resistance is calculated with the coefficients and a differential voltage. Then, a normalized voltage is calculated using the voltage per resistance, the differential voltage, and the bridge resistance to indirectly compensating for temperature. A pressure is calculated with the coefficients and the normalized voltage.

Abstract: A temperature and pressure measuring circuit is provided. The circuit comprises an uncompensated pressure transducer, an analog-to-digital converter, a reference resistive device, and first and second switches. The transducer has variable resistive devices between first, second, third, and fourth bridge nodes. The analog-to-digital converter has first and second reference inputs and first and second differential inputs. When the first switch couples the first differential input and the third bridge node and the second switch couples the second differential input and a ground, a bridge voltage is measurable and a bridge resistance is ratiometrically determinable. The bridge resistance is employed to calculate a temperature. When the first switch couples the first differential input and the first bridge node and the second switch couples the second differential input and the second bridge node, a differential voltage is measurable. The differential voltage is employed to calculate a pressure.

Abstract: A tank monitoring apparatus, having an externally protruding antenna, has the externally protruding antenna to a monitor housing with a liquid-tight compression fitting which provides a fluid-tight seal between the antenna and the housing.

Abstract: A system and method of verifying the installation and data path used by a tank level monitor is provided. Once an installer completes the installation of the tank level monitor, the monitor is activated. The monitor performs a self test and transmits information to a data center. Preferably, the transmission is via a cellular communication network. Once the data center receives the information from the newly installed tank level monitor, the data center generates a text based message that is sent to the installer to verify that the installation was successful. The message from the data center is preferably an email message that can be delivered to a wireless messaging device held by the installer. The generation and transmission of the verification message should be approximately immediate, and certainly within five minutes to provide rapid feed back to the installer.

Abstract: A method, apparatus, and system for remotely monitoring a liquid level in a tank are provided by broadcasting a signal indicative of the liquid level in the tank directly to a cellular communication network from a stand-alone liquid level monitor operatively attached to the tank. The stand-alone monitor is battery powered and includes a processor configured for conserving power by operating the monitor according to a periodic sampling and broadcast schedule, which may be modified by signals received at the monitor directly from the cellular communications network.

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.