Abstract: An apparatus and system for measuring levels of two or more materials maintained within a storage tank using a combination of both a capacitance sensor and a time domain reflectometry (“TDR”) waveguide sensor is disclosed. The apparatus includes a combined circuit for the capacitance sensor and TDR sensor that creates a separation between the return signal from the capacitance sensor and the TDR sensor. The need for the return signal separation is due to the generation of false reflection signals from the capacitance circuitry. In a preferred embodiment, the separation in time is created by moving the capacitance false reflections further in time than the true signal returns. An alternative preferred embodiment would delay the true TDR signals passed the capacitance false reflections. Another alternative preferred embodiment would provide a substantially matched impedance of the capacitance circuit to the TDR circuit, to substantially eliminate the false reflections.

Abstract: A Modbus data protocol register formatting system and method are disclosed. The system and method provide for the Modbus communications protocol request and recall of data stored in a register in the data base native format, and the conversion of the data into a different requested format. The system and method similarly provide for the writing of data into a device register from a known variable format into the data base native format. The ability to convert the data by a format converter after recalling the data, or before storing the data, obviates the need to store or write data in different or multiple formats. The inventive method uses a modified register mapping that comprises defined mapping elements identifying the data address location, the requested data format, along with the data variable. The register mapping is fully variable to provide for a wide range of data formats and data address formats.

Abstract: A measurement system having a first and second seal to create a sealed interface with a fluid and further having a rupturable barrier configured to relieve pressure when the pressure imparted to the first seal is less than the pressure imparted to the second seal, is disclosed. More particularly, the pressure relief element, which may be a rupturable barrier, is configured and positioned so that the second seal pressure limit is less than the first seal pressure limit. The primary elements of the system include the system housing, a sensing element having a first seal, with the sensing element within the housing, a second seal in fluid communication with the first seal, and a barrier that is rupturable when the pressure on the first seal is less than the pressure on the second seal.

Abstract: An apparatus and method for measuring the level of a wide range of varied surfaces or materials housed within vessels, and for detecting contact with a solid surface within the vessel is disclosed. A high precision radio frequency admittance measuring system, using capacitance to measure levels of process materials, coupled with detection element to sense contact of the detection element with a solid surface, such as a floating roof. An active element and ground element in coaxial relationship provides means for measuring the level of process materials including water, oil, kerosene, jet fuel, gasoline. Along with detecting the level of a solid surface within the vessel such as a floating roof. One preferred application of the inventive apparatus is to provide vessel or tank overfill protection. The apparatus detection element is capable of sensing level and non-level solid surfaces.

Abstract: An ultrasonic ranging device for ultrasonic ranging in the near zone. The device may include a transducer for generating an ultrasonic signal and for detecting an echo signal. The device may also include a processor for calculating the distance to a target object based on a first time period defined by a first set of ultrasonic signals when the target object is located outside the near zone and a second time period defined by a second set of ultrasonic signals when the target object is located within the near zone. The processor may also adjust the amplitude of the generated ultrasonic signal until the first set of ultrasonic signals is detected at the transducer.

Abstract: A Modbus data protocol register formatting system and method are disclosed. The system and method provide for the Modbus communications protocol request and recall of data stored in a register in the data base native format, and the conversion of the data into a different requested format. The system and method similarly provide for the writing of data into a device register from a known variable format into the data base native format. The ability to convert the data by a format converter after recalling the data, or before storing the data, obviates the need to store or write data in different or multiple formats. The inventive method uses a modified register mapping that comprises defined mapping elements identifying the data address location, the requested data format, along with the data variable. The register mapping is fully variable to provide for a wide range of data formats and data address formats.

Abstract: Embodiments of systems include primary and secondary seals, and pressure-relief devices that are configured and positioned so that the secondary seals can have maximum rated capacities substantially less than those of the primary seals.

Abstract: An ultrasonic ranging device for ultrasonic ranging in the near zone. The device may include a transducer for generating an ultrasonic signal and for detecting an echo signal. The device may also include a processor for calculating the distance to a target object based on a first time period defined by a first set of ultrasonic signals when the target object is located outside the near zone and a second time period defined by a second set of ultrasonic signals when the target object is located within the near zone. The processor may also adjust the amplitude of the generated ultrasonic signal until the first set of ultrasonic signals is detected at the transducer.

Abstract: A system and method is provided for automatically setting a threshold for a point level device without having a user select whether a point level element is covered or uncovered. A first and second value is measured from a point level element. Whether the point level element is covered or uncovered is determined based on whether the second measured value has increased or decreased with respect to the first measured value. A threshold value is determined based on at least one of the first and second measured values.

Abstract: A system and method is provided for automatically setting a threshold for a point level device without having a user select whether a point level element is covered or uncovered. A first and second value is measured from a point level element. Whether the point level element is covered or uncovered is determined based on whether the second measured value has increased or decreased with respect to the first measured value. A threshold value is determined based on at least one of the first and second measured values.

Abstract: A process control device is disclosed. The process control device comprises a measuring circuit (102) and a power regulator circuit (100). The measuring circuit (102) is coupled to the power regulator (100), and produces a control signal indicative of a measured value. The power regulator circuit (100) redirects a portion of the available power from the power regulator circuit (100) in proportion to the control signal produced by the measuring circuit (102) such that it does not limit available power to the measuring circuit (102). The process control device also may comprise a power control circuit (101) coupled to the measuring circuit (102). The power control circuit (101) redirects an amount of available power from the power regulator circuit (100) in proportion to the control signal. The process control device also comprisies two or more conductors (106, 107) that are in electrical communication with the power regulator circuit (100) and the power control circuit (101).

Abstract: A measuring system for measuring a variable physical parameter by varying a reference signal above and below the magnitude of the physical parameter. The difference between the varying reference and the varying physical parameter is used to create an output signal representative of the magnitude of the parameter. A preferred embodiment of the invention uses a feedback-controlled system to vary the reference in such manner as to cause the time integral of the difference to be minimized. The reference is varied at a controlled rate, and the direction in which the reference is being varied is reversed when a function of the difference reaches some predetermined level. A function of the limits between which the reference has recently been varied is representative of the magnitude of the physical parameter.