Method for robust gauging accuracy for level gauges under mismatch and large opening effects in stillpipes and related apparatus

摘要

A method includes transmitting (302) wireless signals towards a material (104) in a tank (102) and receiving (304) wireless signals reflected off the material. The method also includes calculating (306) a phase velocity of the wireless signals reflected off the material and identifying (308) a level of the material in the tank using the phase velocity. Calculating the phase velocity of the wireless signals could include identifying (404) a plurality of linearly-spaced frequencies and performing (406) linear interpolation using the data identifying the wireless signals to identify data points at the linearly-spaced frequencies. The identification of the data points at the linearly-spaced frequencies could represent the only interpolation operation performed during the calculation of the phase velocity and the identification of the level of the material. Moreover, a mismatch could exist between an inner diameter of a stillpipe (106) through which the wireless signals are transmitted and a diameter of an antenna (112) used to receive the wireless signals.