US 2003/0154784 A1 · Level indicator

Abstract

A level indicator and method is provided which is intimately affixed to the outside surface of the outside wall of a container, for use in the determination of the level of the interface between a mass of flowable material and the void volume above it within a container. The level indicator includes a thermochromataic layer which has at least two thermochromatic materials. Each of the thermochromatic materials responds chromatically within a different operating temperature range. In one embodiment, the level indicator vertically extends substantially the height of the container. In an alternative embodiment, the level indicator vertically extends along the height of the container, in the region of the top portion of the container, and at least above the legal safe-fill level of the flowable material within the container such that overfilling of the flowable material in the container is detectable.

Claims25

Dependent claims

A level indicator which is intimately affixed to the outside surface of the outside wall of a container for use in determining the level of the interface between a mass of flowable material and the void volume above said mass of flowable material within a container;

wherein said flowable material within the container has fluidic properties, and said flowable material has a faster rate of heat transfer than said void volume above it within the container;
said level indicator being in the form of an elongated strip, vertically extending along the height of the container,
wherein said level indicator conforms to the contour of the outside surface of the outside wall of the container such that said level indicator is in intimate heat transfer relationship with the outside wall of the container;
wherein said level indicator includes a thermochromatic layer, said thermochromatic layer has at least two thermochromatic materials, and said at least two thermochromatic materials are arranged in at least two regions;
wherein each of said at least two regions of thermochromatic materials is arranged in an individual area, and each of said thermochromatic materials responds chromatically within a different operating temperature range;
and
wherein said regions of said at least two thermochromatic materials are disposed in arrays thereof arranged along the length of said level indicator.

4 more elements

A method of determining the level of the interface between a mass of flowable material and the void volume above said mass of flowable material within a container using a level indicator which is intimately affixed to the outside surface of the outside wall of the container;

wherein said flowable material within the container has fluidic properties, and said flowable material has a faster rate of heat transfer than said void volume above it within the container;
said level indicator being in the form of an elongated strip, vertically extending along the height of the container,
wherein said level indicator conforms to the contour of the outside surface of the outside wall of the container such that said level indicator is in intimate heat transfer relationship with the outside wall of the container;
wherein said level indicator includes a thermochromatic layer, said thermochromatic layer has at least two thermochromatic materials, and said at least two thermochromatic materials are arranged in at least two regions;
wherein each of said at least two regions of thermochromatic materials is arranged in an individual area, and each of said thermochromatic materials responds chromatically within a different operating temperature range;
and
wherein said regions of said at least two thermochromatic materials are disposed in arrays thereof arranged along the length of said level indicator;
said method comprising the steps of:
(i) inducing heat transfer between said level indicator and said mass of flowable material within said container;
and
(ii) discerning visually a color change in said at least one region of said array of said level indicator;
wherein said region which responds chromatically to a temperature change is contiguous to said mass of flowable material within said container;
wherein step (i) is achieved by selecting any one of the steps chosen from the group of steps consisting of:
(a) spraying a liquid onto the outer surface of said level indicator;
(b) wetting the outer surface of said level indicator with a moistened cloth or sponge;
(c) pouring a liquid down the outer surface of said level indicator;
(d) trickling a liquid down the outer surface of said level indicator;
and
(e) applying an electrically energized source along the length of said of said level indicator.

16 more elements

Dependencies are inferred from the claim text.

Level indicator

Life of this patent

Level indicator

Life of this patent

Abstract

Claims25