Abstract: In a pulse-echo ranging system an energy pulse is transmitted to a target, echo pulses are received and converted into an echo signal that is processed to identify an echo from the target and to determine the distance from the propagation time of the identified echo, where the advanced stage of the processing is performed digitally. Instead of storing and processing the echo signal, the first derivative of the whole echo signal is stored in digital form and then processed to allow for storing as large a number of samples possible in a limited memory without reducing the resolution and without complicating the processing.

Abstract: In a pulse-echo measuring system, echo signals are compared by a difference calculator with the output of a model simulating the system. The detected differences are used to re-calculate parameters in the model. Other parameters are directly measured and applied to the model. A primary measurement, such as level, is detected more accurately and other parameters such as froth height and turbulence are estimated accurately.

Abstract: In a pulse-echo ranging system an energy pulse is transmitted to a target, echo pulses are received and converted into an echo signal that is processed to identify an echo from the target and to determine the distance from the propagation time of the identified echo, where the advanced stage of the processing is performed digitally. Instead of storing and processing the echo signal, the first derivative of the whole echo signal is stored in digital form and then processed to allow for storing as large a number of samples possible in a limited memory without reducing the resolution and without complicating the processing.

Abstract: A method of operating an acoustic pulse echo ranging system is provided. A series of acoustic energy pulses of successively increasing or decreasing burst frequencies are transmitted through a transducer assembly. For each transmitted energy pulse associated echoes are received and converted into an echo function over time. The obtained echo function is stored in a two-dimensional pattern whose first dimension is the burst frequency and whose second dimension is the time. Based upon the two-dimensional pattern a frequency response function is evaluated as a function of echo function values over burst frequency at a selected point of time.

Abstract: To provide a simpler and less expensive system for multipoint level measurement, a level measurement system with at least two sensor devices operating in accordance with the pulse-echo principle and being connected via a communication network to a central signal processing device is provided. The computation-intensive evaluation of echo profiles for calculating distances or ranges is thus shifted from the sensor devices at the measurement locations or sites to the central signal processing device.

Abstract: A time-of-flight calibration system for a radar-based measurement device is provided. The time-of-flight calibration system includes a target antenna and a waveguide, e.g. a coaxial cable. The waveguide is coupled at one end to the target antenna and terminated at its other end by a wave-reflecting impedance.

Abstract: A pulse radar ranging system having a measurement channel and a reference channel is described. In the measurement channel containing an antenna and a measurement target, the normal measurement is performed by processing an echo from the target. In the reference channel containing signal delay means, a reference echo is processed to obtain temperature compensation information.

Abstract: In a pulse-echo measuring system, echo signals are compared by a difference calculator with the output of a model simulating the system. The detected differences are used to re-calculate parameters in the model. Other parameters are directly measured and applied to the model. A primary measurement, such as level, is detected more accurately and other parameters such as froth height and turbulence are estimated accurately.

Abstract: A method of operating an acoustic pulse echo ranging system is provided. A series of acoustic energy pulses of successively increasing or decreasing burst frequencies are transmitted through a transducer assembly. For each transmitted energy pulse associated echoes are received and converted into an echo function over time. The obtained echo function is stored in a two-dimensional pattern whose first dimension is the burst frequency and whose second dimension is the time. Based upon the two-dimensional pattern a frequency response function is evaluated as a function of echo function values over burst frequency at a selected point of time.

Abstract: The transducer circuit includes a transducer component, a drive circuit for the transducer component, a control port for coupling the drive circuit to a control unit and a modulator. The modulator has an input port for receiving a signal or data from another device. The modulator has an output which is coupled to an output stage in the drive circuit. The modulator operates to transmit data, received at the input port, through the drive circuit and the control port to a control unit.

Abstract: A pulse radar ranging system having a measurement channel and a reference channel is described. In the measurement channel containing an antenna and a measurement target, the normal measurement is performed by processing an echo from the target. In the reference channel containing signal delay means, a reference echo is processed to obtain temperature compensation information.

Abstract: To provide a simpler and less expensive system for multipoint level measurement, the level measurement system comprises at least two sensor devices operating in accordance with the pulse-echo principle and being connected via a communication network to a signal processing device. The computation-intensive evaluation of echo profiles for calculating distances or ranges is thus shifted from the sensor devices at the measurement locations or sites to the central signal processing device. A clean copy of the Abstract that incorporates the above amendments is provided herewith on a separate page.

Abstract: A time-of-flight calibration system for a radar-based measurement device is provided. The time-of-flight calibration system includes a target antenna and a waveguide, e.g. a coaxial cable. The waveguide is coupled at one end to the target antenna and terminated at its other end by a wave-reflecting impedance.

Abstract: An embedded calibration mechanism and method for a time-of-flight ranging system. The calibration mechanism (200) comprises a channel (202) having known characteristics. Periodically or as part of a calibration function, a pulse is transmitted through the calibration channel (202) and parameters such transmit pulse delay time and apparent velocity are determined. The calibration parameters or measurements are used to calibrate or compensate operation or measurements from the measurement channel.

Abstract: A protection circuit for a current loop powered level measurement or time of flight ranging apparatus. The protection circuit includes one or more Zener diodes, a leakage current detector circuit and a compensating current circuit. The leakage current detector circuit detects the leakage currents flowing from the Zener diodes and generates an output for the compensating current circuit. The compensating current circuit generates a compensating current so that the sum of the leakage currents and the compensating current remains a constant and the loop current is not affected by variations in the leakage currents for example as a result of variations in the voltage in the current loop or temperature of the device.

Abstract: A protection circuit for a current loop powered level measurement or time of flight ranging apparatus. The protection circuit includes one or more Zener diodes, a leakage current detector circuit and a compensating current circuit. The leakage current detector circuit detects the leakage currents flowing from the Zener diodes and generates an output for the compensating current circuit. The compensating current circuit generates a compensating current so that the sum of the leakage currents and the compensating current remains a constant and the loop current is not affected by variations in the leakage currents for example as a result of variations in the voltage in the current loop or temperature of the device.

Abstract: An embedded calibration mechanism and method for a time-of-flight ranging system. The calibration mechanism (200) comprises a channel (202) having known characteristics. Periodically or as part of a calibration function, a pulse is transmitted through the calibration channel (202) and parameters such transmit pulse delay time and apparent velocity are determined. The calibration parameters or measurements are used to calibrate or compensate operation or measurements from the measurement channel.

Abstract: A level measurement apparatus for determining the level of a material received in a container is provided. The apparatus includes a transducer for emitting energy pulses and receiving reflected energy pulses, and circuitry operably coupled to the transducer. The circuitry includes a component for controlling the transducer. The circuitry also includes a component for determining level measurement based on the time elapsed between an emission of an energy pulse and a reception of the energy pulse reflected by the surface of the material. The apparatus also includes a programmable module operably coupled to the circuitry. The programmable module includes a component for receiving user programs for controlling the operation of the circuitry. Different embodiments of the level measurement apparatus, and a method and system for programming a level measurement apparatus are also provided.

Abstract: A microwave-based level measurement system having a planar microwave antenna configuration. According to another aspect, the microwave-based level measurement devices are field interchangeable with ultrasonic based level measurement devices.

Abstract: A method of operating a pulse echo ranging system comprising a transducer assembly for providing transmission and reception of high frequency energy pulses at substantially different plural frequencies. The method uses signals received by the transducer assembly to generate an echo profile for signals received at at least a first of the frequencies to enhance the recovery of data beyond that obtained from the first signal alone.