Abstract: A method of storage tank monitoring including calculating liquid inventory within the storage tank. Real-time parameters associated with evaporative loss of a liquid stored within the storage tank are determined to produce input data. The real-time parameters include at least one condition within the storage tank and at least one environmental condition. Evaporative loss is automatically calculated with an inventory calculation algorithm using the input data and at least one known physical property of the liquid in the storage tank.

Abstract: An apparatus includes a stable local oscillator, which includes a first control loop. The first control loop includes a first voltage-controlled oscillator configured to generate a first output signal and a first phase-locked loop. The apparatus also includes a frequency up-converter configured to increase a frequency of the first output signal. The apparatus further includes a second control loop configured to receive the up-converted first output signal. The second control loop includes a second voltage-controlled oscillator configured to generate a second output signal and a second phase-locked loop. The second control loop may further include a mixer having a first input coupled to the frequency up-converter, a second input coupled to the second voltage-controlled oscillator, and an output coupled to the second phase-locked loop. A reference frequency source may be configured to generate a signal identifying a reference frequency and to provide that signal to the phase-locked loops.

Abstract: A method of storage tank monitoring including calculating liquid inventory within the storage tank. Real-time parameters associated with evaporative loss of a liquid stored within the storage tank are determined to produce input data. The real-time parameters include at least one condition within the storage tank and at least one environmental condition. Evaporative loss is automatically calculated with an inventory calculation algorithm using the input data and at least one known physical property of the liquid in the storage tank.

Abstract: A method includes lowering a sensor unit in a tank, where the tank is capable of receiving a material. The method also includes determining a first distance between the material and the sensor unit and determining a second distance between the sensor unit and a main unit that lowers the sensor unit. In addition, the method includes determining a level of the material in the tank using the first and second distances. The method could further include calibrating the sensor unit to compensate for variations in a medium within the tank, where the sensor unit transmits wireless signals through the medium to determine the first distance. Determining the first distance could include using an ultrasonic measurement technique, and determining the second distance could include using a non-contact servo measurement technique.

Abstract: The invention relates to a method for accurately determining the level L of a liquid by means of radar signals emitted to the liquid surface and radar signals reflected from the liquid surface. The invention further relates to a device for accurately determining the level of a liquid by means of the method according to the invention, which device comprises at least a radar antenna disposed above the liquid for emitting radar signals to the liquid and receiving radar signals reflected from the liquid surface, as well as means for determining the liquid level on the basis of the emitted radar signals and the reflected radar signals.

Abstract: A method includes retrieving at least one first measurement associated with material in a tank from a memory at a level gauge. The method also includes comparing the at least one first measurement to at least one second measurement associated with the material in the tank. The method further includes determining whether a difference between the at least one first measurement and the at least one second measurement exceeds a threshold. In addition, the method includes identifying a current level of the material in the tank in a first manner if the difference does not exceed the threshold or a second manner if the difference does exceed the threshold. The first manner could include correcting a level measurement using the difference between the at least one first measurement and the at least one second measurement. The second manner could include identifying an offset value based on differences between pairs of level measurements.

Abstract: A multi-sensor method and system for imaging and inspecting a storage tank that holds a liquid. The system includes an infrared sensor including a scanning vertical mount positioned outside the storage tank, an ultrasonic sensor array positioned outside the storage tank, and at least one of an ultrasonic sensor positioned inside the storage tank and a phased array radar positioned inside the storage tank secured to an interior top surface of the storage tank. The system further includes a processor coupled to receive multi-sensor data from the infrared sensor, ultrasonic sensor array and at least one of the ultrasonic sensor in the tank and the phased array radar. The processor fuses the multi-sensor data to generate a sludge level image profile for sludge in the storage tank, a liquid level image for liquid in the storage tank, and optionally an integrity profile for a shell of the storage tank.

Abstract: A method includes transmitting wireless signals towards a material in a tank and receiving wireless signals reflected off the material. The method also includes calculating a phase velocity of the wireless signals reflected off the material and identifying a level of the material in the tank using the phase velocity. Calculating the phase velocity of the wireless signals could include identifying a plurality of linearly-spaced frequencies and performing linear interpolation using the data identifying the wireless signals to identify data points at the linearly-spaced frequencies. The identification of the data points at the linearly-spaced frequencies could represent the only interpolation operation performed during the calculation of the phase velocity and the identification of the level of the material. Moreover, a mismatch could exist between an inner diameter of a stillpipe through which the wireless signals are transmitted and a diameter of an antenna used to receive the wireless signals.

Abstract: A device for metering fluids includes a block provided with a channel connecting a fluid inlet in fluid communication with a fluid outlet. The device also includes a filter assembly within the channel and a fluid meter within the channel at a position downstream from the filter assembly. The device further includes a check valve assembly within the channel at a position downstream from the fluid meter. In addition, the device includes a calibration valve assembly within a channel section of the channel between the fluid outlet and the fluid meter. The calibration valve assembly is operable to move between a first position allowing passage of fluid from the fluid meter towards the fluid outlet and a second position blocking the passage of fluid from the fluid meter towards the fluid outlet.

Abstract: A system includes a probe configured to be raised and lowered in a tank that is configured to receive a material. The system also includes a connector coupled to the probe and having at least one type of coding encoded on the connector. The system further includes a main unit configured to raise and lower the probe using the connector, digitally capture information associated with the at least one type of coding on the connector, determine a level reading identifying a level of the material in the tank using the captured information, and wirelessly transmit the determined level reading.

Abstract: A method includes receiving data identifying wireless signals including wireless signals reflected off a surface of material in a tank and detecting a plurality of reflection peaks associated with the wireless signals. The method also includes classifying at least some of the detected reflection peaks and tracking at least some of the classified reflection peaks. The method further includes identifying a level of the material using at least one of the tracked reflection peaks. The classified peaks could include main-mode and/or high-mode reflection peaks, where the material level is identified using the main-mode peak or using an estimated location of the main-mode peak based on the high-mode peak. The classified peaks could also include level, bottom, and obstruction peaks, where the material level is identified by using a known permittivity, the bottom peak, and a tank height to estimate a location of the level peak when the level peak is lost or obscured.

Abstract: The invention relates to a method for determining the level L of a liquid within a specified measuring range by means of radar signals transmitted to the liquid surface and radar signals reflected from the liquid surface, comprising the steps of i) transmitting radar signals to the liquid surface in time sequence; ii) receiving radar signals reflected from the liquid surface in time sequence; iii) determining the level L partially on the basis the transmitted radar signals and the reflected radar signals. The invention further relates to a device for determining the level L of a liquid within a specified measuring range, at least comprising a radar antenna disposed above the liquid for transmitting radar signals to the liquid and receiving radar signals reflected from the liquid surface, as well as means for determining the liquid level L on the basis of the transmitted radar signals and the reflected radar signals.

Abstract: A method includes receiving information associated with a level of material in a tank, where the tank has a hatch. The method also includes determining whether the level of material in the tank experiences a specified variation within a critical zone associated with the hatch. The specified variation is indicative of the hatch being open while the tank is being filled. In addition, the method includes generating an alarm when the level of material in the tank experiences the specified variation. Determining whether the level of material in the tank experiences the specified variation could be based on an entrance level speed of the material, which identifies a rate at which the level of material in the tank is increasing when the material level crosses a lower bound of the critical zone. Also, no alarms could be generated when the level of material in the tank is outside the critical zone.

Abstract: The invention relates to a method for accurately determining the level L of a liquid by means of radar signals emitted to the liquid surface and radar signals reflected from the liquid surface. The invention further relates to a device for accurately determining the level of a liquid by means of the method according to the invention, which device comprises at least a radar antenna disposed above the liquid for emitting radar signals to the liquid and receiving radar signals reflected from the liquid surface, as well as means for determining the liquid level on the basis of the emitted radar signals and the reflected radar signals.

Abstract: A system and method are provided that receive a signal representing a reflection of an electromagnetic wave from a liquid and from one or more reference pins in a storage tank. A sensed distance to the liquid and one or more sensed distances to the pins are calculated from the signal, and the sensed distances to the pins are compared to one or more reference distances. A correction factor is calculated based on the comparison of the sensed distances and the reference distances, and a corrected distance to the liquid is calculated based on the correction factor and the sensed distance to the liquid. While the storage tank is empty, a reference signal representing a reflection of an electromagnetic wave from the reference pins may be obtained and reference sensed distances to the reference pins calculated and stored as the reference distances.

Abstract: A method includes transmitting wireless signals toward material in a tank. The method also includes receiving first return wireless signals reflected off a surface of the material and identifying a level of the material in the tank using the first return wireless signals. The method further includes receiving second return wireless signals reflected off a bottom of the tank and determining whether the material has been adulterated using the level of the material in the tank and the second return wireless signals. Determining whether the material has been adulterated could include determining a dielectric constant of the material, determining a density of the material using the dielectric constant of the material, and comparing the determined density of the material against a specified density. Determining the dielectric constant of the material could include using a time between peaks associated with the first and second return wireless signals.

Abstract: A system includes a probe configured to be raised and lowered in a tank capable of receiving a material. The system also includes a connector coupled to the probe and having at least one type of coding encoded on the connector. The system further includes a main unit configured to raise and lower the probe using the connector, digitally capture information associated with the at least one type of coding on the connector, determine a level reading identifying a level of the material in the tank using the captured information, and wirelessly transmit the identified level reading. The main unit could also be configured to determine a confidence level or interval associated with the identified level reading and wirelessly transmit the confidence level or interval. The connector could include a tape, and the at least one type of coding could include visible markings, perforations, and/or magnetic codes.

Abstract: A method includes receiving an image of a storage tank at a processing system, where the storage tank is capable of storing one or more materials. The method also includes processing the image to identify a level, profile, or amount of sludge or sediment present in the storage tank. Processing the image could include segmenting the image into multiple segments and using the segments to identify a non-linearity in the image. The image could be segmented into segments having different grey levels using grey level values associated with previously-identified sediment or sludge. The identified level or amount of sludge or sediment could be used to automatically schedule maintenance for the storage tank.

Abstract: A method includes receiving data identifying wireless signals including wireless signals reflected off a surface of material in a tank and detecting a plurality of reflection peaks associated with the wireless signals. The method also includes classifying at least some of the detected reflection peaks and tracking at least some of the classified reflection peaks. The method further includes identifying a level of the material using at least one of the tracked reflection peaks. The classified peaks could include main-mode and/or high-mode reflection peaks, where the material level is identified using the main-mode peak or using an estimated location of the main-mode peak based on the high-mode peak. The classified peaks could also include level, bottom, and obstruction peaks, where the material level is identified by using a known permittivity, the bottom peak, and a tank height to estimate a location of the level peak when the level peak is lost or obscured.

Abstract: An apparatus includes a stable local oscillator, which includes a first control loop. The first control loop includes a first voltage-controlled oscillator configured to generate a first output signal and a first phase-locked loop. The apparatus also includes a frequency up-converter configured to increase a frequency of the first output signal. The apparatus further includes a second control loop configured to receive the up-converted first output signal. The second control loop includes a second voltage-controlled oscillator configured to generate a second output signal and a second phase-locked loop. The second control loop may further include a mixer having a first input coupled to the frequency up-converter, a second input coupled to the second voltage-controlled oscillator, and an output coupled to the second phase-locked loop. A reference frequency source may be configured to generate a signal identifying a reference frequency and to provide that signal to the phase-locked loops.