ROSEMOUNT TANK RADAR AB

A radar level gauge system comprising a transmission line probe; a transceiver coupled to the transmission line probe, the transceiver comprising: a first signal generator connected to the transmission line probe and controllable to generate a transmit signal to include a measurement sweep across frequencies defined by a first frequency and a second frequency; a second signal generator configured to generate an offset signal having a constant frequency lower than the first frequency; a first mixer for mixing the transmit signal and the offset signal to form a first mixer output signal; and a second mixer for mixing the first mixer output signal and the reflection signal to form a second mixer output signal; and processing circuitry coupled to the transceiver and configured to determine the filling level based on the second mixer output signal.

A method for replacing a first sensor with a second sensor in a field device system configured to determine a process variable, each of the first and second sensor provided with near field communication, NFC, functionality, the method includes: connecting the second sensor to an initiation device and initiating the second sensor based on information uniquely identifying the first sensor; disconnecting the second sensor from the initiation device; placing the second sensor in the vicinity of the first sensor; with the first sensor connected to a power source and the second sensor not connected to a power source, communicatively connecting the sensors via NFC and transferring settings from the first to the second sensor; replacing the first sensor with the second sensor; connecting the first sensor to the initiation device; and transferring a verification from the first sensor to the initiation device confirming that the transfer of settings was completed.

A field device comprising a first loop terminal and a second loop terminal; a measurement unit; a loop current control device for controlling the loop current to encode a process variable determined by the measurement unit, the loop current control device being provided in the electric circuit between the first loop terminal and an a first node of the electric circuit; an asymmetrically conducting device provided in the electric circuit between the first node of the electric circuit and a second node of the electric circuit; an energy storage device in the electric circuit between the second node of the electric circuit and the second loop terminal; and a controllable shunt regulator provided in the electric circuit between the first node of the electric circuit and the second loop terminal, wherein the measurement unit is in the electric circuit between the second node and the second loop terminal.

A vibrating fork level sensor probe arrangement for a tank comprising: a first vibrating fork level sensor; a second vibrating fork level sensor; and a pipe configured to hold the first vibrating fork level sensor in a first position and to hold the second vibrating fork level sensor in a second position at a predetermined distance from the first vibrating fork level sensor, wherein the first and second vibrating fork level sensors are configured to determine a location of an interface of a material in the tank.

A radar level gauge system comprising a first microwave unit including a transmitter patch for transmitting a first transmit signal, a receiver patch for receiving a first reflection signal, and processing circuitry for determining a first level measurement; a second microwave unit including a transmitter patch for transmitting a second transmit signal, a receiver patch for receiving a second reflection signal, and processing circuitry for determining a second level measurement; an antenna; and a signal coupling arrangement including a first hollow waveguide directional coupler, a second hollow waveguide directional coupler, and a signal combiner.

A field device comprising measurement circuitry; loop current circuitry; voltage measurement circuitry; and a controller configured to: acquire a first value of a process variable; determine if the voltage received by the field device is sufficient to support a first loop current; control, when the voltage is insufficient to support the first loop current, the loop current to an alarm current lower than a predefined alarm threshold current; acquire a second value of the process variable and a present voltage received by the field device; determine a second loop current; determine, based on the present voltage and an estimation of a loop impedance, whether or not the present voltage is sufficient for supporting the second loop current; and control, when it is determined that the present voltage received by the field device from the current loop is sufficient, the loop current from the alarm current to the second loop current.

A method of determining a filling level of a product in a tank using a radar level gauge system comprising a transceiver, an antenna, and processing circuitry, the method comprising the steps of: generating and transmitting a transmit signal; receiving a reflection signal resulting from reflection of the transmit signal; determining based on the transmit signal and the reflection signal, for each surface echo candidate, a first measure indicative of a distance and a second measure indicating a rate-of-change distribution of the distance; assigning one surface echo candidate as most likely to correspond to single reflection of the transmit signal at the surface of the product, based on an evaluation of the second measure for each surface echo candidate; and determining the filling level based on the first measure for the assigned surface echo candidate.

A guided wave radar level gauge for determining a fill level of a product contained in a tank comprising: a measurement unit; a probe; and control circuitry configured to: transmit a signal along the probe; receive a reflected signal; detect a first peak in the received signal, the first peak having a first amplitude exceeding a first threshold amplitude; determine that no second peak having an amplitude exceeding a second threshold amplitude is detected; apply a sliding window peak detection algorithm to the signal to detect a second peak in the signal; and determining a location of a material interface based on the location of the second peak.

A method of determining a filling level of a product in a tank, comprising the steps of: generating an electromagnetic transmit signal exhibiting a measurement sweep across a time series of piece-wise constant frequencies being within a measurement frequency range starting at a first frequency, and ending at a second frequency higher than the first frequency, a difference between frequencies in each pair of adjacent frequencies in the frequency range being equal to the first frequency; guiding the transmit signal towards and into the product in the tank; guiding an electromagnetic reflection signal back towards the transceiver; mixing the reflection signal with an electromagnetic reference signal, resulting in a mixer output indicative of a difference between the reflection signal and the reference signal; forming a measurement signal based on the mixer output; and determining the filling level based on the measurement signal.

A guided wave radar level gauge for determining a fill level of a product contained in a tank for high-pressure applications including a transceiver, a probe a reference reflector and control circuitry configured to perform a distance measurement to determine a measured distance to the reference reflector; determine a first dielectric constant of a vapor in the tank based on the measured distance to the reference reflector and a reference distance to the reference reflector; acquire a temperature or pressure of the vapor in the tank; determine a second dielectric constant of the vapor in the tank based on the acquired temperature or pressure; and compare a difference between the first and second dielectric constant of the vapor in the tank with a predetermined difference threshold value.