Abstract: System for monitoring a floating roof of a tank containing a liquid, wherein the system determines a local status of the floating roof in spaced apart sensing element locations. In a hazardous or potentially hazardous environment, there is an on-roof subsystem including a sensing element in each sensing element location, intrinsically safe measuring circuitry coupled a sensing elements and arranged for determining said local status, intrinsically safe radio communication on-roof circuitry coupled for communicating externally of the on-roof subsystem the local, an intrinsically safe power supply circuitry connected to an intrinsically safe and interchangeable energy storage unit for powering the on-roof subsystem. The system further includes monitoring circuitry for receiving the indication of local status and for determining an overall monitored status of said floating and further radio communication circuitry. The on-roof subsystem is wireless in its power supply and communication.

Abstract: A method for identifying an undesired condition in the function of a floating roof of a tank, the method comprising determining a filling level of a product in the tank, detecting a reference distance between a reference position on the roof and the surface using a level gauge mounted on the roof, forming a reference distance deviation as a difference between the reference distance and an expected value, and comparing the reference distance deviation with a specified range. If the reference distance deviation is outside the specified range, a data set including the reference distance deviation and the filling level is stored. These steps are repeated for a plurality of points in time, and the undesired condition is then identified based on stored data sets of reference distance deviations and filling levels. The present invention thus provides an economical method to provide diagnostics of a floating tank roof.

Abstract: A method of calibrating a level gauge system using electromagnetic signals to determine a filling level of a product in a tank. The level gauge system comprises a real time sampler for sampling a reflection signal with a sampling period between consecutive samples. The method comprises the steps of: receiving timing signals from a wireless communication network; generating time stamp signals based on the timing signals; registering a number of the sampling periods between a first time stamp signal and a second time stamp signal; and determining the sampling period based on the registered number of sampling periods and a time between the first time stamp signal and the second time stamp signal. Various embodiments of the present invention provide for high accurate determination of the filling level in a tank without the need for a temperature stable and highly accurate clock reference in the level gauge system.

Abstract: A method for identifying an undesired condition in the function of a floating roof of a tank, the method comprising determining a filling level of a product in the tank, detecting a reference distance between a reference position on the roof and the surface using a level gauge mounted on the roof, forming a reference distance deviation as a difference between the reference distance and an expected value, and comparing the reference distance deviation with a specified range. If the reference distance deviation is outside the specified range, a data set including the reference distance deviation and the filling level is stored. These steps are repeated for a plurality of points in time, and the undesired condition is then identified based on stored data sets of reference distance deviations and filling levels. The present invention thus provides an economical method to provide diagnostics of a floating tank roof.

Abstract: System for monitoring a floating roof of a tank containing a liquid, wherein the system determines a local status of the floating roof in spaced apart sensing element locations. In a hazardous or potentially hazardous environment, there is an on-roof subsystem including a sensing element in each sensing element location, intrinsically safe measuring circuitry coupled a sensing elements and arranged for determining said local status, intrinsically safe radio communication on-roof circuitry coupled for communicating externally of the on-roof subsystem the local, an intrinsically safe power supply circuitry connected to an intrinsically safe and interchangeable energy storage unit for powering the on-roof subsystem. The system further includes monitoring circuitry for receiving the indication of local status and for determining an overall monitored status of said floating and further radio communication circuitry. The on-roof subsystem is wireless in its power supply and communication.

Abstract: A method of calibrating a level gauge system using electromagnetic signals to determine a filling level of a product in a tank. The level gauge system comprises a real time sampler for sampling a reflection signal with a sampling period between consecutive samples. The method comprises the steps of: receiving timing signals from a wireless communication network; generating time stamp signals based on the timing signals; registering a number of the sampling periods between a first time stamp signal and a second time stamp signal; and determining the sampling period based on the registered number of sampling periods and a time between the first time stamp signal and the second time stamp signal. Various embodiments of the present invention provide for high accurate determination of the filling level in a tank without the need for a temperature stable and highly accurate clock reference in the level gauge system.

Abstract: The present invention relates to a gauging system, comprising a gauge configured to sense a process variable and to provide process data representative of the process variable, a processing unit connected to the gauge, the processing unit comprising power supply circuitry configured to receive power from a remote external power source and to provide regulated power, and first circuitry configured to receive process data from the gauge and to superimpose the process data onto the regulated power forming a power signal, and a wireless communication unit electrically connected to the processing unit by means of a two-wire control loop, the wireless communication unit comprising second circuitry configured to receive the power signal and to separate the process data from the regulated power, an antenna, and radio frequency (RF) communication circuitry being powered by means of the regulated power from the second circuitry, configured to receive process data from the second circuitry, and to transmit RF signals re

Abstract: The present invention relates to a gauging system, comprising a gauge configured to sense a process variable and to provide process data representative of the process variable, a processing unit connected to the gauge, the processing unit comprising power supply circuitry configured to receive power from a remote external power source and to provide regulated power, and first circuitry configured to receive process data from the gauge and to superimpose the process data onto the regulated power forming a power signal, and a wireless communication unit electrically connected to the processing unit by means of a two-wire control loop, the wireless communication unit comprising second circuitry configured to receive the power signal and to separate the process data from the regulated power, an antenna, and radio frequency (RF) communication circuitry being powered by means of the regulated power from the second circuitry, configured to receive process data from the second circuitry, and to transmit RF signals re

Abstract: A method and system for determining a product level in a tank which determine a first level measure using emission of electromagnetic waves into the tank, detect a differential pressure, determine an observed density based on the detected differential pressure and the first level measure, and determine a second level measure based on the observed density and a currently measured differential pressure. The present invention is based on the realization that a level measurement based on differential pressure and an observed density can provide a valuable redundant level measurement, which can provide increased reliability and enable detection of errors.

Abstract: A tank gauging system for sensing product parameters of a product contained in a tank is disclosed. The system comprises a microwave-based level gauging unit and a temperature gauging unit. A controller of the system includes an external interface adapted to enable communication between the tank gauging system and an external control system; processing circuitry configured for management of communication over the external interface; and a power supply, which is enclosed in an explosion-proof housing and configured to supply intrinsically safe power to the gauging units, wherein the power supply has an essentially rectangular output characteristic. Further, an intrinsically safe two-wire bus connecting the controller and the gauging units is provided, wherein the two-wire bus is usable both for transmitting measurement signals related to the sensed product parameters from the gauging units to the controller and for providing intrinsically safe power from the controller to the gauging units.

Abstract: A method and system for determining a product level in a tank, comprising determining a first level measure using emission of electromagnetic waves into the tank, detecting a differential pressure, determining an observed density based on the detected differential pressure and the first level measure, and determining a second level measure based on the observed density and a currently measured differential pressure. The present invention is based on the realization that a level measurement based on differential pressure and an observed density can provide a valuable redundant level measurement. Such a redundant measurement can provide increased reliability and enable detection of errors.

Abstract: A tank gauging system for sensing product parameters of a product contained in a tank is disclosed. The system comprises a microwave-based level gauging unit and a temperature gauging unit. A controller of the system includes an external interface adapted to enable communication between the tank gauging system and an external control system; processing circuitry configured for management of communication over the external interface; and a power supply, which is enclosed in an explosion-proof housing and configured to supply intrinsically safe power to the gauging units, wherein the power supply has an essentially rectangular output characteristic. Further, an intrinsically safe two-wire bus connecting the controller and the gauging units is provided, wherein the two-wire bus is usable both for transmitting measurement signals related to the sensed product parameters from the gauging units to the controller and for providing intrinsically safe power from the controller to the gauging units.

Abstract: The present invention relates to the field of radar level gauging systems, in which a level of a surface of a product stored in a container is measured. The gauging system comprises: a radar level gauge arranged above the surface of the product which is arranged to transmit a microwave signal towards the product surface and receive a reflected microwave signal from the product surface; a calculation unit arranged to determine a measured value of the product level based upon the received signal; means for comparing the measured value of the product level with a predetermined value; and a second level gauge arranged closed to the bottom of the container and arranged to determine the product level when the measured value is below the predetermined value.

Abstract: The present invention relates to the field of radar level gauging systems, in which a level of a surface of a product stored in a container is measured. The gauging system comprises: a radar level gauge arranged above the surface of the product which is arranged to transmit a microwave signal towards the product surface and receive a reflected microwave signal from the product surface; a calculation unit arranged to determine a measured value of the product level based upon the received signal; means for comparing the measured value of the product level with a predetermined value; and a second level gauge arranged closed to the bottom of the container and arranged to determine the product level when the measured value is below the predetermined value.