Patent ID: 8218396

Claim:
A level measurement system suitable for use in a high temperature and pressure environment to measure the level of coolant fluid within the environment, the system comprising: a vessel defining a high temperature and pressure environment containing a coolant fluid; an ultrasonic waveguide comprising a plurality of magnetostrictive stripes positioned within the high temperature and pressure environment so that a portion of the waveguide is surrounded by the coolant fluid; a magnetostrictive electrical assembly located within the high temperature and pressure environment and configured to operate in the environment and cooperate with the waveguide to launch and receive ultrasonic waves along the waveguide, the magnetostrictive electrical assembly comprising a magnetostrictive send/receive coil and a magnetostrictive bias coil that surround the portion of the waveguide having the magnetostrictive stripes; and an external signal processing system located outside of the high temperature and pressure environment and configured for communicating with the electrical assembly located within the high temperature and pressure environment; wherein speed of the ultrasonic waves along the waveguide is proportional to the density of the coolant fluid surrounding the waveguide, and the level thereof, is obtained by measuring the transit time for the ultrasonic wave to progress down the waveguide and reflect back to the magnetostrictive electrical assembly.