Patent ID: 6795015
Filing Date: 2004-09-21
Classification: G01F,H01Q

Abstract:
A bottom reflector for a radar-based level gauge, which measures a level of a liquid stored in a tank by means of transmitting a microwave signal towards the surface of the liquid from the top of the tank, receiving the microwave signal as reflected against the surface of the liquid, and calculating the level of the liquid stores in the tank from the propagation time of the transmitted and reflected microwave signal, said bottom reflector being mountable at a predetermined height in said tank for reflecting the microwave signal when no liquid is present at said predetermined height in the tank, wherein said bottom reflector comprises a reflecting structure having a first reflection coefficient for said microwave signal when the level of the liquid is above the reflecting structure and a second reflection coefficient for said microwave signal when the level of the liquid is below the reflecting structure, said first reflection coefficient being substantially lower than said second reflection coefficient.