PULSED LEVEL GAUGE SYSTEM WITH CONTROLLABLE DELAY PATH THROUGH SELECTED NUMBER OF DELAY CELLS

摘要

A level gauge system comprising transmission signal generating circuitry for generating a transmission signal in the form of a sequence of transmission pulses;a propagation device connected to the transmission signal generating circuitry and arranged to propagate the transmission signal towards a surface of the product inside the tank, and to return a reflected signal resulting from reflection of the transmission signal at the surface of the product contained in the tank. The level gauge system further comprises reference signal providing circuitry configured to provide a reference signal in the form of a sequence of reference pulses. At least one of the transmission signal generating circuitry and the reference signal providing circuitry comprises delay circuitry for providing a time-varying phase difference between the transmission signal and the reference signal. The delay circuitry comprises a plurality of delay cells, and controllable switching circuitry arranged and configured to allow formation of a delay path comprising a subset of the plurality of delay cells connected in series, to thereby allow control of a signal propagation delay of the delay circuitry.