Abstract: A level measurement instrument comprises an analog circuit for transmitting a pulse signal at a target of interest and receiving reflected echoes of the pulse signal and developing an echo waveform representative of the reflected echoes. A programmed digital circuit is operatively coupled to the analog circuit and comprises a programmed controller and memory. The controller is operatively programmed to identify peaks in the echo waveform and store an active peak list in the memory from a current measurement scan and a buffer peak list from prior measurement scans. The controller is further programmed to match peaks in the active peak list to peaks in the buffer peak list, to select a target peak from the active peak list based on which of the matched peaks have moved, and determining material level responsive to the target peak.

Abstract: A level measurement instrument comprises an analog circuit for transmitting a pulse signal at a target of interest and receiving reflected echoes of the pulse signal and developing an echo waveform representative of the reflected echoes. A programmed digital circuit is operatively coupled to the analog circuit and comprises a programmed controller and memory. The controller is operatively programmed to identify peaks in the echo waveform and store an active peak list in the memory from a current measurement scan and a buffer peak list from prior measurement scans. The controller is further programmed to match peaks in the active peak list to peaks in the buffer peak list, to select a target peak from the active peak list based on which of the matched peaks have moved, and determining material level responsive to the target peak.

Abstract: A process measurement instrument includes a fiducial and is adapted for detection of the fiducial. The instrument includes an interface circuit comprising a drive circuit for transmitting a pulse signal at the fiducial and at a target of interest and a receive circuit receiving reflected echoes of the pulse signal and developing an analog receive signal representative of the reflected echoes. A processing circuit is operatively coupled to the interface circuit for receiving the analog receive signal and comprising a threshold detector detecting if the analog receive signal is above a select threshold value. A controller is operatively coupled to the processing circuit and responsive to leading and trailing edges of the reflected echo for the fiducial and determining an average of the leading and trailing edges to determine location of the fiducial.

Abstract: A process measurement instrument includes a fiducial and is adapted for detection of the fiducial. The instrument includes an interface circuit comprising a drive circuit for transmitting a pulse signal at the fiducial and at a target of interest and a receive circuit receiving reflected echoes of the pulse signal and developing an analog receive signal representative of the reflected echoes. A processing circuit is operatively coupled to the interface circuit for receiving the analog receive signal and comprising a threshold detector detecting if the analog receive signal is above a select threshold value. A controller is operatively coupled to the processing circuit and responsive to leading and trailing edges of the reflected echo for the fiducial and determining an average of the leading and trailing edges to determine location of the fiducial.

Abstract: A measurement instrument comprises a sensor circuit comprising a drive circuit for transmitting a pulse signal at a target of interest and a receive circuit receiving reflected echoes of the pulse signal and developing an analog signal representative of the reflected echoes. An analog processing circuit is operatively coupled to the sensor circuit for receiving the analog signal and comprising a gate for selectively transferring the analog signal to a comparator that compares the gated analog signal to a select threshold level to develop a data signal representative of location of the target of interest. A programmed digital processing circuit is operatively coupled to the sensor circuit and the analog processing circuit and comprises a measurement module to control the drive circuit and evaluate the data signal to determine material location.

Abstract: A process measurement instrument with target rejection comprises a sensor circuit. The sensor circuit comprises a drive circuit for transmitting a pulse signal at a target of interest and a receive circuit receiving reflected echoes of the pulse signal and developing an analog receive signal representative of the reflected echoes. An analog processing circuit receives the analog receive signal and comprises a summer subtracting an analog target rejection signal from the analog receive signal to develop a corrected receive signal. A programmed digital processing circuit is operatively coupled to the analog processing circuit and comprises a memory storing target rejection signal value data representing false target reflections and developing the analog target rejection signal for transfer to the analog processing circuit.

Abstract: A measurement instrument comprises a sensor circuit comprising a drive circuit for transmitting a pulse signal at a target of interest and a receive circuit receiving reflected echoes of the pulse signal and developing an analog signal representative of the reflected echoes. An analog processing circuit is operatively coupled to the sensor circuit for receiving the analog signal and comprising a gate for selectively transferring the analog signal to a comparator that compares the gated analog signal to a select threshold level to develop a data signal representative of location of the target of interest. A programmed digital processing circuit is operatively coupled to the sensor circuit and the analog processing circuit and comprises a measurement module to control the drive circuit and evaluate the data signal to determine material location.

Abstract: A process measurement instrument with target rejection comprises a sensor circuit. The sensor circuit comprises a drive circuit for transmitting a pulse signal at a target of interest and a receive circuit receiving reflected echoes of the pulse signal and developing an analog receive signal representative of the reflected echoes. An analog processing circuit receives the analog receive signal and comprises a summer subtracting an analog target rejection signal from the analog receive signal to develop a corrected receive signal. A programmed digital processing circuit is operatively coupled to the analog processing circuit and comprises a memory storing target rejection signal value data representing false target reflections and developing the analog target rejection signal for transfer to the analog processing circuit.