초록 ▼

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 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.

대표청구항 ▼

1. 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

1. 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 at least two thermochromatic materials are directly applied to the outside surface of the outside wall of the container;wherein at least a portion of the outside surface of the outside wall of the container which underlies said level indicator has been treated by an application method chosen from the group consisting of anodizing, anti-oxidizing, rust-proofing, and combinations thereof, so as to provide at least that portion of the outside surface of the outside wall with a light absorbing property, prior to the direct application of said level indicator to the outside surface of 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; andwherein said regions of said at least two thermochrornatic materials are disposed in arrays thereof arranged along the length of said level indicator. 2. The level indicator of claim 1, wherein said level indicator vertically extends along the height of the container, at least in the region of the top portion of the container, and at least above the legal safe-fill level of said flowable material within said container such that overfilling of said flowable material in the container is detectable. 3. The level indicator of claim 1, wherein said thermochromatic layer further includes a light absorbing background upon which said at least two regions of thermochromatic materials are arranged. 4. The level indicator of claim 1, wherein each of said at least two thermochromatic materials is directly applied to the outside surface of the outside wall of the container by an application method chosen from the group consisting of painting, silk screening, stencilling, molding, crayon transfer, pencil transfer, screening, and combinations thereof, and wherein each of said at least two thermochromatic materials is carried to the outside surface of the outside wall of the container during the application method by a transfer medium. 5. The level indicator of claim 1, wherein said flowable material is chosen from the group consisting of liquefied gas, corrosive liquid, water, alcohol, oil, coffee, tea, juice, milk, and granular material. 6. The level indicator of claim 1, wherein said level indicator is intimately affixed to the outside surface of the outside wall of a container chosen from the group of containers consisting of pressurized cylinders, open containers, sealed containers, cryogenic flasks, and opaque vessels for determining the level of the interface between said mass of flowable material and said void volume above said mass of flowable material within the container to which said level indicator is intimately affixed. 7. The level indicator of claim 1, further including a protective clear lamina, wherein said protective clear lamina overlies said at least two thermochromatic materials. 8. The level indicator of claim 7, wherein said protective clear lamina is an ultraviolet filter. 9. The level indicator of claim 1, wherein said thermochromatic materials are chosen from the group of cholesteric liquid crystal compounds and mercurous oxide. 10. The level indicator of claim 1, wherein said at least two thermochromatic materials in said array have overlapping temperature ranges. 11. The level indicator of claim 1, wherein said regions of thermochromatic materials are arranged on said outside surface of said outside wall of said container chosen from the group of arrays consisting of one of said regions of thermochromatic materials vertically positioned down the center of said level indicator and at least one other region diagonally positioned on each side of said vertically positioned region of said level indicator, all of said regions of thermochromatic materials vertically positioned upon said level indicator, and all of said regions of thermochromatic materials horizontally positioned upon said level indicator. 12. The level indicator of claim 1, wherein said at least two adjacent regions of thermochromatic materials are arranged to form a set, and wherein said set is disposed vertically along the length of said level indicator in a repeated manner. 13. 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 at least two thermochromatic materials are directly applied to the outside surface of the outside wall of the container;wherein at least a portion of the outside surface of the outside wall of the container which underlies said level indicator has been treated by an application method chosen from the group consisting of anodizing, anti-oxidizing, rust-proofing, and combinations thereof so as to provide at least that portion of the outside surface of the outside wall with a light absorbing property, prior to the direct application of said level indicator to the outside surface of 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; andwherein 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) pouri ng 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. 14. The method of claim 13, wherein said liquid in any of steps (a) through (d) is a heat source, and wherein said liquid is at a temperature which is above the temperature of said flowable material within the container so as to induce heat transfer from said liquid to said flowable material within the container. 15. The method of claim 13, wherein said liquid in any of steps (a) through (d) is a heat sink; and wherein said liquid is at a temperature which is below the temperature of said flowable material within the container so as to induce heat transfer to said liquid from said flowable material within the container. 16. The method of claim 13, wherein said at least two adjacent regions are arranged to form a set; wherein said set comprises said at least two thermochromatic materials, and wherein said set is disposed vertically along the length of said level indicator in a repeated manner. 17. The method of claim 16, wherein said plurality of sets are disposed in a repeated manner vertically along the length of said level indicator, and said method further comprises the step of:(iii) estimating the level of the interface between said mass of flowable material and said void volume above said mass of flowable material within the container using said level indicator, wherein the estimated area falls between a level having a profound color change and a level having a faint color change.