摘要 |
<p>A sensor is provided for determining the surface or interface level of a material comprising: a pulse generator (46) for generating electrical transmit pulses; a guide wire (14) at least partially immersed in the material; a conductor (19, 21) electrically coupling the pulse generator (46) and the guide wire (14), the conductor (19, 21) conducting the transmit pulses such that the transmit pulses are at least partially reflected by the surface or interface and converted to corresponding electrical reflected impulses; a sample and hold circuit (50) connected to the conductor (19, 21) for sampling said reflected pulses; and means for determining a time delay between said transmitted and reflected pulses for establishing the surface or interface level. A method for determining the surface or interface level of a material is also provided. <IMAGE></p> |