INDICATING DEVICE

• US 3,620,677 A
• Filed: 12/18/1961
• Issued: 11/16/1971
• Est. Priority Date: 12/18/1961
• Status: Expired due to Term

• Current Assignee: Ayers Morison
• Original Assignee: Ayers Morison
• Inventors: Morison, Ayers
• Primary Examiner(s): Joseph Scovronek
• Application Number:
  US04/160,127
• Time in Patent Office: 3,620 Days
• Field of Search: 73/53,29,358,335 58/1 99/192TI 116/114.19,114,114.20 158/96 67/53,70,71,69 117/121.2,140R 252/425.5 23/253TP,254 55/387 261/99,107
• US Class Current: 422/423
• CPC Class Codes: B01D 15/08 Selective adsorption, e.g. chromatography
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: G01K 3/04 in respect of time
• CPC Class Codes: G01N 11/00 Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
• CPC Class Codes: G01N 13/02 Investigating surface tension of liquids
• CPC Class Codes: G01N 30/6065 with varying cross section
• CPC Class Codes: G01N 30/92 Construction of the plate
• CPC Class Codes: G01N 31/22 using chemical indicators G01N31/02 takes precedence
• CPC Class Codes: G01N 33/04 Dairy products
• CPC Class Codes: Y10T 137/5444 Lever actuator

Abstract

1. An indicating device comprising in combination a porous capillary material characterized by connected voids of sufficiently small size to induce the progressive absorption of a fluid, and an impervious covering material enclosing at least the major portion of the exterior surfaces of said capillary material and disposed in intimate contact therewith defining an absorptive cavity of a preselected volume, said device constructed to provide directional guidance through said absorptive cavity of a fluid contacting an exposed surface of said capillary material, indicating means on said indicating device, said capillary material within said absorptive cavity operable in conjunction with a fluid absorbed to evidence in combination with said indicating means a characteristic of the fluid absorbed therein.

Claims

1. AN INDICATING DEVICE COMPRISING IN COMBINATION A POROUS CAPILLARY MATERIAL CHARACTERIZED BY CONNECTED VOIDS OF SUFFICIENTLY SMALL SIZE TO INDUCE THE PROGRESSIVE ABSORPTION OF A FLUID, AND IMPERVIOUS COVERING MATERIAL ENCLOSING AT LEAST THE MAJOR PORTION OF THE EXTERIOR SURFACES OF SAID CAPILLARY MATERIAL AND DISPOSED IN INTIMATE CONTACT THEREWITH DEFINING AN ABSORPTIVE CAVITY OF A PRESELECTED VOLUME, SAID DEVICE CONSTRUCTED TO PROVIDE DIRECTIONAL GUIDANCE THROUGH SAID ABSORPTIVE CAVITY OF A FLUID CONTACTING AN EXPOSED SURFACE OF SAID CAPILLARY MATERIAL, INDICATING MEANS ON SAID INDICATING DEVICE, SAID CAPILLARY MATERIAL WITHIN SAID ABSORPTIVE CAVITY OPERABLE IN CONJUNCTION WITH A FLUID ABSORBED TO

2. An indicating device comprising in combination a porous capillary material characterized by connected voids of sufficiently small size to induce the progressive absorption of a fluid, and an impervious covering material enclosing the exterior surfaces of said capillary material and disposed in intimate contact therewith defining an absorptive cavity of a preselected volume, closure means on said indicating device including a portion of said covering material adapted to be removed for exposing a selected portion of said capillary material, said device constructed to provide directional guidance through said absorptive cavity of a fluid contacting the exposed portion of said capillary material, indicating means on said indicating device, said capillary material within said absorptive cavity operable in conjunction with a fluid absorbed to evidence in combination with said indicating means a characteristic of the fluid absorbed therein.

3. An indicating device comprising in combination a porous capillary material characterized by connected voids of sufficiently small size to induce the progressive absorption of a fluid, said capillary material formed in a preselected configuration and of a controlled porosity to provide for controlled changes in the absorption characteristics thereof, and an impervious covering material enclosing at least the major portion of the exterior surfaces of said capillary material and disposed in intimate contact Therewith defining an absorptive cavity of a preselected volume, said device constructed to provide directional guidance through said absorptive cavity of a fluid contacting an exposed surface of said capillary material, indicating means on said indicating device, said capillary material within said absorptive cavity operable in conjunction with a fluid absorbed to evidence in combination with said indicating means a characteristic of the fluid absorbed therein.

4. An indicating device comprising in combination a porous capillary material characterized by connected voids of sufficiently small size to induce the progressive absorption of a fluid, and an impervious covering material enclosing at least the major portion of the exterior surfaces of said capillary material and disposed in intimate contact therewith defining an absorptive cavity of a preselected volume, said device constructed to provide directional guidance through said absorptive cavity of a fluid contacting an exposed surface of said capillary material, indicating means on said indicating device, said capillary material within said absorptive cavity operable in conjunction with a fluid absorbed to evidence in combination with said indicating means a characteristic of the fluid absorbed therein, said covering material formed with a venting aperture therethrough disposed in communication with said capillary material at a position located remote to said exposed surface of said capillary material for venting the interior thereof.

5. A continuous strip of indicating material comprising in combination an elongated porous capillary material characterized by connected voids of sufficiently small size to induce the progressive absorption of a fluid, and an elongated impervious covering material enclosing the exterior surfaces of said capillary material and disposed in intimate contact therewith, said strip adapted to be cut at longitudinally spaced intervals forming a plurality of indicating devices of a preselected length, each of said indicating devices having the opposite ends of said capillary material exposed and defining between said ends an absorptive cavity of a preselected volume, indicating means on each of said indicating devices, each of said indicating devices constructed to provide directional guidance through said absorptive cavity of a fluid contacting an exposed end of said capillary material, said capillary material within said absorptive cavity operable in conjunction with a fluid absorbed to evidence in combination with said indicating means a characteristic of the fluid absorbed therein.

6. An indicating device as defined in claim 1 further characterized as including a plurality of pieces of said capillary material each having the major portion of the exterior surface thereof enclosed within said covering material and separated from the next adjacent one of said pieces defining therewith a plurality of individual absorptive cavities.

7. The indicating device as defined in claim 1 wherein said capillary material is in the form of a substantially rectangular planar strip of substantially constant cross section throughout its length.

8. The indicating device as defined in claim 1 wherein said capillary material is of a controlled configuration comprising an inlet section of a substantially constant cross section disposed in absorptive contact with a second section of a cross section different than that of said inlet section.

9. The indicating device as defined in claim 1 wherein said capillary material is in the form of a circular disc of relative constant thickness throughout and wherein the fluid to be absorbed is adapted to be introduced through said impervious covering material at substantially the center of said disc.

10. The indicating device as defined in claim 1 wherein said capillary material is of a composite construction including a first section of a controlled shape and porosity disposed in absorptive contact with a second section of a controlled different shape and poRosity.

11. An indicating device comprising in combination a porous capillary material characterized by connected voids of sufficiently small size to induce the progressive absorption of a fluid, and an impervious covering material enclosing at least the major portion of the exterior surfaces of said capillary material and disposed in intimate contact therewith defining an absorptive cavity of a preselected volume, said device constructed to provide directional guidance through said absorptive cavity of a fluid contacting an exposed surface of said capillary material, said capillary material further characterized as incorporating an impregnant on the internal surfaces thereof which is operative in response to and in conjunction with the absorption of a fluid therethrough to provide a visual indication of the depth of penetration of the fluid or of a selected component thereof through said capillary material within said absorptive cavity.

12. The indicating device as described in claim 11 wherein said impregnant comprises an acid-base indicator which is operative to change color to indicate the relative proportion of the penetration of the acid-base constituents of the fluid absorbed in said absorptive cavity.

13. The indicating device as defined in claim 11 wherein said impregnant comprises a reactive material which is operative to react with the fluid or selected components thereof and an indicator impregnated in said capillary material for visually indicating the proportion of said reactive material that has reacted within said absorptive cavity.

14. An indicating device comprising in combination a porous capillary material characterized by connected voids of sufficiently small size to induce the progressive absorption of a fluid, and an impervious covering material enclosing at least the major portion of the exterior surfaces of said capillary material and disposed in intimate contact therewith defining an absorptive cavity of a preselected volume, said device constructed to provide directional guidance through said absorptive cavity of a fluid contacting an exposed surface of said capillary material, said capillary material further characterized as possessing ion exchange characteristics on the internal surfaces thereof for selectively adsorbing selected ions in the fluid absorbed, and indicator means in said capillary material for visually indicating the relative proportion of said capillary material within said absorptive cavity which contains the adsorbed selected ions.

15. Analytical indicator characterized by prolonged shelf-life comprising a substantially plane paper sheet having a wettable surface impregnated with a reagent for producing a contrasting color with respect to said paper sheet on spreading of a liquid containing the substance of interest thereover as visual evidence of the presence of said substance of interest in said liquid, said indicator including superposed upper and lower layers of a water-insoluble plastic material, with the paper sheet therebetween, said upper and lower plastic layers overlying, respectively, substantially the entire upper and lower surfaces of the paper, said plastic layers extending beyond two opposite edge portions of the test paper and being joined along the edges thereof disposed outwardly of the strip forming a close-fitting closure about the test paper, at least one end of the closure being open, said test paper being united to at least one surface of said plastic layers.

16. Analytical indicator characterized by prolonged shelf-life comprising a substantially plane paper sheet having a wettable surface impregnated with a reagent for producing a contrasting color with respect to said paper sheet on spreading of a liquid containing the substance of interest thereover as visual evidence of the presence of said substance of interest in said liquid, said indicator including superposed upper and lower layers of a water-insoluble plastic material, with the paper sheet therebetween, said upper and lower plastIc layers overlying, respectively, substantially the entire upper and lower surfaces of the paper and extending beyond two opposite edges of the test paper and being joined along the edges thereof disposed outwardly of the strip forming a close-fitting closure about the test paper, at least one end of the closure being open.

17. Analytical indicator according to claim 16 wherein one of said water-insoluble plastic sheets comprises a plastic coated paper.

18. An indicator including a series of interconnected analytical test paper units characterized by prolonged shelf-life comprising a plurality of substantially plane paper sheets having wettable surfaces impregnated with a reagent for producing a contrasting color with respect to said paper sheets on spreading of the liquid containing the substance of interest thereover as visual evidence of the presence of said substance of interest in said liquid, said indicator including superposed upper and lower elongated layers of water-insoluble plastic material, with the paper sheets disposed at spaced intervals therebetween along the length of said layers, said upper and lower plastic layers overlying, respectively, substantially the entire upper and lower surfaces of the paper and being joined along transverse portions thereof along the transverse edge portions of each paper sheet, forming a close-fitting closure about each sheet, at least one longitudinal edge portion of each closure being open.

19. An indicator having prolonged shelf-life characteristics comprising a substantially plane paper sheet having a wettable surface impregnated with a reagent for producing a contrasting color with respect to said paper sheet on spreading of the liquid containing the subject of interest thereover as visual evidence of the presence of said substance of interest in said liquid and at least one paper sheet comprising a color comparison scale, said indicator including superposed upper and lower elongated layers of water-insoluble plastic material, with the paper sheets disposed at spaced intervals therebetween along the length of said layers, said upper and lower plastic layers overlying, respectively, substantially the entire upper and lower surfaces of the paper and being joined along transverse portions thereof along the transverse edge portions of each paper sheet forming a close-fitting closure about each sheet, at least one longitudinal edge portion of each closure being open.

20. An indicator for carrying out multiple determinations having prolonged shelf-life characteristics comprising at least two substantially plane paper sheets having wettable surfaces, each of said paper sheets having been impregnated with a reagent for producing a contrasting color respectively with respect to said paper sheet on spreading of a liquid containing the subject of interest thereover as visual evidence of the presence of said substance of interest in said liquid, said indicator including superposed upper and lower elongated layers of water insoluble plastic material, with the paper sheets disposed at spaced intervals therebetween along the length of said layers, said upper and lower plastic layers overlying, respectively, substantially the entire upper and lower surfaces of the paper and being joined along transverse portions thereof along the transverse edge portions of each paper sheet forming a close-fitting closure about each sheet, at least one longitudinal edge portion of each closure being open.

21. Analytical test tape of indefinite length characterized by prolonged shelf-life comprising an indicator paper in strip form, and upper and lower strips of hermetically sealing sheet material disposed one above and one below the indicator paper strip covering the same in close-fitting overlying relation, said layers extending beyond the width of the indicator paper strip and being joined together along longitudinal edge portions outwardly of the strip, said layers being transversely disconnected at one end of the tape, providing an opening for access to the indicator paper, at least one of the said strips of sealing sheet material being transparent.