This paper describes a novel, noninvasive method for measurement of
liquid level in closed metal tanks that are under high pressure. It is
based on the use of ultrasonic Lamb waves propagating along the tank
wall. Contact with liquid substantially changes the characteristics of
these waves and this can be used as an indicator of liquid presence.
Theoretical analysis shows that the symmetric and antisymmetric Lamb
wave modes, both fundamental and higher order, are sensitive to presence
of the liquid. The optimal wave frequency depends on the thickness of
the tank wall and wall material. A prototype liquid level sensor based on this
principle has been developed.
It uses two pairs of wedge transducers to generate and detect Lamb waves
propagating along the circumference of the gas tank. An operating
frequency of 100 kHz is found to be optimal for use with tanks having a
wall thickness of 30-50 mm. Prototype sensors developed under this
program have been used successfully in oil fields in the far northern
region of Russia.
ISweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
没有评论:
发表评论