Patent ID: 8794063

Claim:
A layer height measuring system comprising: a transmission line including a probe for measuring a height of a first layer within a tank and a cable that connects the probe to an electronics unit; the electronics unit cyclically transmitting interrogation pulses to the probe and receiving reflections therefrom for time domain reflectometric measurement of the height of the first layer; a memory; and a processor configured by the memory to perform the steps of: detecting first and second impedance transitions corresponding to first and second boundaries of a bounded region of known length; optimizing a sweep offset and a sweep gain so as to cause swept sample collection to occur substantially only within the bounded region; and detecting a third impedance transition within the bounded region, the third impedance transition corresponding to an interface between the first layer and a second layer, the first and second layers having respectively different dielectric constants, wherein at least one of said first and second impedance transitions comprises a fluid-fluid interface.