Abstract: A dual temperature indicator providing visual indications when exposed to predetermined high or low temperatures. The indicator has a bulb with a capillary tube and an attached high temperature indicator structure. The bulb has a first liquid which also fills a predetermined portion of the tube. A separating substance and a second miscible liquid further fills a predetermined portion of the remainder of the tube. At a predetermined low temperature, the liquid in the bulb contracts causing the separating substance and a portion of the second liquid to move into the bulb to produce a visible color change. The high temperature indicator structure has an indicating member in contact with the capillary tube end and which provides a visual indication at a predetermined high temperature when the liquids expand upon an environmental temperature increase.

Abstract: A warmer used to warm fluids, such as blood or the like, passed into the human body. Air is introduced through an opened windowed membrane to expose chemicals in a container. A chemical reaction with the air causes a heat reaction of the chemicals. A tube engages in a trough in the container adjacent where the chemical reaction takes place, thereby absorbing the heat of the chemical reaction for warming the fluids, such as blood, saline solution, injectable solutions in trauma, pre-surgical, intra-surgical, post-surgical and any other solutions through the tube.

Abstract: Indicating device suitable for visibly indicating conditions such as the application of force or pressure or the exposure to a critical temperature. The device includes a porous pad containing an indicating dyed chemical, a wick maintained in spaced relation to the pad and a snap action activating means. The activating means forces the wick into contact with the pad and dyed chemical migration provides visible indication of the application of force or pressure. The indicating dyed chemical may be frozen and the activating means engaged. Upon reaching a critical temperature the frozen chemical melts allowing dye migration into the wick and a visible indication of exposure to the critical temperature.

Abstract: A critical temperature indicator is provided utilizing the volume reduction characteristics of organic compounds as they undergo a change from the liquid state to the solid state. The bulb and a portion of the capillary tube of a thermometer-like structure contains a colorless organic compound. Another organic compound saturated with a dye, which compound has a solidification temperature lower than that of the colorless compound and which is miscible with the colorless compound, is located in the capillary tube and separated from the colorless compound by a solid, movable plug or a liquid which is immiscible with either the colorless or the dyed compound. The volume of the colorless compound upon solidification is less than the volume of the bulb so that the separating plug or liquid and at least a portion of the dyed compound are drawn into the bulb upon solidification. The dyed compound then mixes with the colorless compound to provide a visual indication that the colorless compound has solidified.

Abstract: A critical temperature indicator is provided utilizing the volume reduction characteristics of organic compounds as they undergo a change from the liquid state to the solid state. A capillary tube sealed at one end contains a first organic compound adjacent the closed end and a second colored organic compound which has a solidification temperature lower than that of the first compound and which is separated from the first compound by a liquid which is immiscible with either the first or the second compounds. The separating liquid also has a solidification temperature lower than that of the first compound. A colorless or white porous plug is located within the separating liquid and frictionally engages the tube to prevent movement of the plug with respect to the tube.

Abstract: A device for monitoring thermal energy input and displaying the relationship of the thermal energy input to a selected time/temperature relationship. The device employs an indicating material which, when melted, expands and flows into a narrow channel to provide an irreversible, visible indication of the thermal energy to which the device has been exposed.

Abstract: A freeze indicating device which provides a visible record when it has been exposed to a specified low temperature such as 0.degree. C. The indicator utilizing a two-chamber, constant volume device, one chamber having a variable volume and another chamber being expandable upon freezing of an aqueous liquid therein. The expansion of the aqueous fluid transmitting pressure to the fluid in the variable volume chamber, thus forcing some of its fluid through a capillary passage onto a visible indicator.

Abstract: Humidity indicating method and device suitable for visibly indicating exposure to a selected humidity level or for indicating a humidity-time history. The device comprises in combination a deliquescent compound, a liquid absorbent wick, and an indicating means. The change in properties of deliquescent compounds are employed to indicate a particular humidity level or a humidity-time history. Preferred methods of making humidity indicating devices are described.

Abstract: Indicating device suitable for visibly measuring parameters such as time, temperature, and time-temperature relationships. The device comprises in combination a porous reservoir pad containing an indicating material, a wick material and activating means. The progress of the indicating material along the wick can be visibly observed to indicate the passage of time, exposure to a given minimum temperature, or a time-temperature relationship. The combination is adapted to conveniently regulate migration of the indicating material from the reservoir pad to the wick. A preferred method for making an indicating device is described.

Abstract: Indicating device suitable for visibly measuring parameters such as time, temperature, and time-temperature relationships. The device includes a porous fluid carrying pad, a wick material for said fluid, and an indicator means whereby the progress of fluid along the wick material can be visibly indicated and used to measure the passage of time, the exposure to a given minimum temperature, or a time-temperature relationship. The combination is adapted to regulate migration of fluid from the fluid source to the wick material.