Patent ID: 8555697

Claim:
A method for determining calibration charts used to determine a level and amount of fuel inside underground fuel tanks ( 1 ) at gas stations comprising the steps of: rotating a laser distance measurement device ( 2 ) located inside an empty underground fuel tank ( 1 ) via at least one main shaft ( 14 ), said rotation being up to 360 degrees in circular direction of B and up to 270 degrees in the upward-downward direction of A, determining distances of the laser distance measurement device ( 2 ) from inner walls of said fuel tank ( 1 ) for separate points by use of a ray ( 3 ) of the laser device, determining an angle X between said fuel tank ( 1 ) and a horizontal plane via at least one inclinometer ( 4 ), transmitting the determined distances between the laser distance measurement device ( 2 ) and the inner walls of the fuel tank ( 1 ) measured at separate points and the angle X as measured by the inclinometer ( 4 ) to a computer ( 18 ) via at least one control unit ( 8 ) and determining by the computer ( 18 ) the calibration chart of the fuel tank ( 1 ) using 3D three dimensional) space points determined from the transmitted distances and the angle X along with 3D (three dimensional) modeling of the inside of the tank.