Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
  • G01K3/00—Thermometers giving results other than momentary value of temperature
  • G01K3/02—Thermometers giving results other than momentary value of temperature giving means values; giving integrated values
  • G01K3/04—Thermometers giving results other than momentary value of temperature giving means values; giving integrated values in respect of time

Definitions

• the present invention relates to a device for detecting and quantitatively measuring the exposure of an object to a temperature at least equal to a predetermined temperature, taking into account the duration of this exposure.
• a concentrate of red blood cells can be stored in a blood bank for forty two days at a temperature between +4 ° C and + 8 ° C. Once distributed by the blood establishment, this concentrate should be used very quickly if the ambient temperature exceeds + 10 ° C. It is therefore important to know the moment when this temperature crossing takes place and to measure the duration to know if the concentrate is still usable.
• the invention therefore more particularly aims to eliminate these drawbacks by means of a device which detects temperature overruns and which integrates over time the amplitude of these overshoots.
• a device comprising an enclosure containing a material changing state or viscosity at a predetermined temperature, a propagation space connected to said enclosure, in which said material in the liquid state can propagate to a predetermined speed and means for viewing by transparency the progress of said material in said space.
• the displacement of the material in the liquid state in said space can be effected by capillary action either in capillary or laminar conduits, or in an absorbent material contained in said space.
• the amplitude of this displacement will be variable as a function of the viscosity and the surface tension of the product, the duration, the temperature and the capacity or the absorption power of the absorbent product.
• the material could then consist of a product with variable viscosity depending on the temperature (for example an oil or a mineral, vegetable or synthetic animal fat) or even a product changing state (solid / liquid) depending on the temperature .
• a product with variable viscosity depending on the temperature for example an oil or a mineral, vegetable or synthetic animal fat
• a product changing state solid / liquid
• the absorbent product may consist of a porous material (chalk, blotting paper, strip of fluocarbon material) or a pulverulent material.
• the display means may involve at least one window allowing the vision of the material propagating in the above space, this material can either be colored so as to be able to be observed directly, or opaque so as to mask a possibly colored surface or graded underlying, either likely to cause a change in the optical property of the absorbent material or capillary or laminar conduits, or likely to cause a visible reaction within the absorbent material (toning of a reagent) -
• this aforementioned space may contain a substance dissolving gradually on contact with the material in the liquid state, means being provided for distinguishing said material from said substance.
• Figures 1 to 3 are schematic views of a detection device according to the invention using a ribbon of porous material, this device being either in longitudinal section (Figure 1), in top view ( Figure 2) and in cross section (Figure 3);
• Figures 4 and 5 schematically show, in top view and in axial section, a detector using a spiral propagation space
• Figure 6 is a schematic cross section illustrating the principle of a display device using a frosted
• Figure 7 is a schematic longitudinal section of another alternative embodiment of the invention involving a process of dissolution or chemical attack of a material.
• Certain products with variable viscosity as a function of temperature for example mineral or vegetable or synthetic oil or grease
• certain products which change state as a function of temperature liquids, crystals, etc.
• an absorbent product for example blotting paper, sugar, absorbent crystals, etc.
• This displacement is variable depending on the viscosity and / or the surface tension of the absorbed product or its state (liquid or solid), the duration, the temperature and the absorption capacity or power of the absorbent product .
• Some absorbent products can change color on contact with an absorbed product or vice versa
• certain absorbed products can change color on contact with an absorbent product (for example chemical reaction between an acidic or basic body and a paper to measure PH) .
• Some absorbed products may change color depending on the temperature.
• edible margarine which is in the solid state is not absorbed by blotting paper.
• the margarine liquefies and is absorbed by the blotting paper.
• This absorption is progressive as a function of duration and is all the more important the greater the absorption capacity of the blotter and the more fluid the body absorbed. If the ambient temperature drops to a level where the margarine resolidifies, the progress on the blotting paper stops to resume if the temperature rises.
• the blotting paper As the blotting paper becomes soaked with the fatty substance, it changes its appearance to take on a transparent oily appearance. If this blotting paper is previously colored on one side, the coloring will be visible on each of the faces of the blotting paper after impregnating the fatty substance. This coloring can have several levels (for example green then red). The progression of the fatty substance on the paper will first reveal a color (for example green) and then after the next color (for example red). This second coloring may indicate the limit not to be reached if the product to which the system is subject is to be used.
• the device according to the invention uses these physical characteristics: change of state or variation of the viscosity of a product as a function of the temperature and transparent display of the absorption of this product by an absorbent body which becomes transparent on contact with the absorbed product.
• the device consists of a housing 1 in the form of a flat strip produced by folding and gluing a sheet of rigid or semi-rigid material such as plastic or cardboard.
• the underside 2 of the box which consists of two juxtaposed folds of the sheet, is covered with an adhesive lining 3 (adhesive layer or double-sided adhesive) covered by a protective film 4.
• the upper face 5 of the housing 1 comprises, at one of its ends, an enclosure 6 projecting outwards which delimits a space at least partially filled with a product 7 with variable state or viscosity.
• This space opens onto the interior volume of the housing 1 through an orifice 8 which can be closed off with an extractable or frangible cover.
• This cover consists here of a tongue 9 of impermeable material, slidingly mounted inside the housing 1 and one end of which protrudes through a slot left free at the end of said housing 1.
• this upper face 5 comprises a series of orifices 10 (at least two) which extend along the longitudinal axis of the housing 1.
• the housing 1 contains a strip of porous material 1 1 which extends over its entire length passing in line with the aforesaid orifices 10 and under the tongue 9 which constitutes the aforesaid seal.
• This strip 1 1 which may consist, for example, of blotting paper or of a porous fluocarbon plastic (for example polytetrafluoroethylene or the like) has the property of being initially opaque and of becoming transparent when it is impregnated with the above material 7 Thus, when it is transparent, it allows vision through the orifices 10 of printed patterns. either on the lower face of the strip 1 1, or on the part of the lower face 2 of the housing 1 in contact with said strip 1 1.
• the tongue 9 is placed so as to close the orifice 8, so that the material 7 contained in the enclosure 6 cannot reach the strip 11 and this, whatever the ambient temperature.
• the operator removes the protective film 4 to fix the housing 1 on the object whose temperature is less than or equal to the predetermined temperature called critical.
• the operator pulls on the tab 9 so as to initiate monitoring.
• the material 7, frozen remains in contact with the strip 1 1 without impregnating it.
• the strip 11 remains opaque and masks the printed patterns located at the right of the orifices 10.
• the material 7 becomes sufficiently fluid to penetrate the pores of the strip 1 1 and gradually impregnate it.
• the strip becomes transparent and this transparency propagates from one end to the other, at a speed and at the end of a predetermined period of time which depend on the absorbance of the strip 1 1 and the surface tension of the material 7.
• the patterns located in line with the orifices 10 become visible and provide a quantitative indication of duration-intensity on the exposure of the object to a temperature higher than the temperature critical.
• this indication will make it possible to know whether the maintenance of the object at the storage temperature has been respected and, if not, whether the object is usable or not. The irreversibility of this indication eliminates any possibility of fraud.
• the device could for example be in the form of a self-adhesive sticker comprising two coaxial discs Di, D 2 placed side by side, namely:
• a support disc D 2 having in its center a convex shape FB, the concave part of which is provided with asperities AS, the lower face of this disc carrying an annular adhesive coating RA covered by a protective film FP,
• An upper disk Di made of transparent material, shaped so as to delimit with the support disk D 2 a central enclosure EC coaxial from which a spiral conduit CS forming the aforesaid propagation space.
• the central enclosure EC is intended to receive a material M] changing state and / or viscosity as a function of the temperature and having either surfactant properties specific to propagation by capillarity, or properties of a solvent, or chemical properties capable of causing the progressive attack of an appropriate material.
• the spiral duct CS can, meanwhile. contain, depending on the nature of the material contained in the enclosure, a porous and / or powdery material, a soluble material, and / or a chemically attackable material.
• the material M) will be hermetically confined in the enclosure thanks to a frangible cover OF whose rupture may be caused by the asperities AS, following a pressure exerted on the domed form FB.
• a frangible cover OF whose rupture may be caused by the asperities AS, following a pressure exerted on the domed form FB.
• the part of the attacked material which is dissolved, then lets appear patterns printed on the support disc.
• This solution has the advantage of being able to use liquids with low viscosity (for example glycol water or an acid solution) as a material changing state.
• liquids with low viscosity for example glycol water or an acid solution
• a laminar propagation space EL delimited on one side by a smooth face FL which can bear patterns, for example colored, and, on the other side, a wall made of transparent material having a frosted face FD.
• the presence of the frosted surface prevents vision of the smooth face, this vision being made possible only by the presence of the liquid propagating in the laminar space EL.
• FIG. 7 shows another alternative embodiment of the invention involving a flat case 1 ′, one of the ends of which is provided with an enclosure enclosure EC / frangible cover OF / convex shape FB provided with asperities AS similar to that of FIGS. 4 and 5.
• this box delimits a propagation space EP containing a material chemically attackable MA by the liquid L contained in the enclosure EC.
• the liquid L discovers a pattern printed on the underside FI of the housing 1 '.
• the latter may contain an absorbent material impregnated with product.
• the tongue used to close the enclosure may be integral with the porous strip and extend it to one side.
• the strip can be movable inside the housing so as to be able to occupy two positions, namely:
• the strip is brought into contact with the material.
• the strip is supplied with porous material contained in the enclosure can be effected by means of a wire made of porous material serving as a flow regulator.
• This solution is particularly suitable for fluids having a low viscosity.
• the housing can be wrapped in a transparent waterproof pouch so as to avoid any degradation of the device due in particular to humidity.
• FIGS. 8 and 9. there is a housing according to FIGS. 8 and 9. containing at least one level of detection of temperature overshoot so as to know with precision the duration and the amplitude of said temperature overshoot.
• This box can also be attached to a recorder thus indicating the day and time when the temperature is exceeded.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Measuring Temperature Or Quantity Of Heat (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9551328

Family Applications (1)

Country Status (6)

Families Citing this family (26)

Family Cites Families (24)

• 2000
  • 2000-08-07 US US10/110,910 patent/US6968804B1/en not_active Expired - Fee Related
  • 2000-08-07 WO PCT/FR2000/002263 patent/WO2001029525A1/fr active Search and Examination
  • 2000-08-07 JP JP2001532069A patent/JP2004500555A/ja not_active Withdrawn
  • 2000-08-07 EP EP00958651A patent/EP1222447A1/de not_active Withdrawn
  • 2000-08-07 CA CA002388361A patent/CA2388361A1/fr not_active Abandoned
  • 2000-08-07 AU AU70102/00A patent/AU7010200A/en not_active Abandoned

Non-Patent Citations (1)

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