Patent ID: 6672156
Filing Date: 2004-01-06
Classification: G01F

Abstract:
An apparatus for measuring liquid level, comprising in combination,a. a vertical ruler passing substantially vertically through one or more liquid interfaces; b. supporting means for said ruler; c. a measurement scale with encoded distance information along the length of said ruler comprised of a sequence of area elements whereby each said area element divides an incident first beam of radiative energy into two or more second beams of radiative energy, where, i. each of said second beams has a propagation direction substantially different from the propagation direction of any other said second beam and substantially different from the propagation direction of said incident first beam; and ii. said area elements divide said first beam into a pattern of said second beams selectively in accordance with a code indicative of distance along said ruler; d. one or more floats that encompass and substantially freely traverse said ruler, wherein each float contains: i. one or more sources of radiative energy for producing and directing said first beams of radiation onto said area elements; ii. one or more radiative energy detectors to indicate second beams of radiation whereby distance information encoded along said ruler is read; and iii. sending means for transmitting said distance information to a data interface unit external to said floats, which is capable of one or more of the following data functions: 1. display 2. storage 3. retransmission. e. means for converting said distance information to liquid interface level.