Abstract: A dual dosimeter system with (1) a stick-on, self-indicating, instant radiation dosimeter applied onto (2) a conventional radiation dosimeter and/or detector for monitoring high energy radiations, such as X-ray, electrons and neutrons. Radiation dosimeters, such as X-ray film and TLD (Thermoluminescence Dosimeters), are highly sensitive but are not instant. Radiation detectors, such Geiger counter, ionization chamber and silicon diode type electronic detectors, are highly sensitive and instant but have several other drawbacks, e.g., they are fragile, bulky, dose rate dependent or require electrical power. In the event of a dirty bomb, nuclear detonation or a radiological accident, one needs to know the harmful high dose (e.g., higher than 0.1 rad) instantly so proper precautions can be taken and medical treatment, if required, can be given to the victim. If a self-indicating instant dosimeter is applied to the conventional dosimeters and detectors, one would know high dose instantly.

Abstract: A device composed of (1) a color changing indicator, (2) an optional polymeric binder, preferably having gel forming capability, and (3) an activator solvent system which induces a color change in the indicator when device is frozen, in the region of about 0 to −30° C. An example of the device is an indicator of a fine dispersion of partially polymerized diacetylene of the formula: R—C═C—C═C—R, where R is a substituent group, e.g., 4BCMU where R=—(CH2)OCONHCH2COO(CH2)4H, dispersed in a mixture of solvents, e.g., 96:4 water:ED (ethylene glycol diacetate), with or without a polymeric binder. When the temperature of the device is lowered to the freezing point of water, the activator solvent phase separates out of the mixture and induces a color change in the indicator. The device can undergo an irreversible color change, e.g., from blue to red, when the activator mixture is frozen in the region of about 0 to 30° C.

Abstract: A moving boundary device for monitoring the time-temperature storage history, i.e. shelf life, of perishable products. The device is constructed of an activator tape, containing an activator composition in an activator matrix, an indicating tape, containing an indicating composition in an indicator matrix in which the matrices are adhered together to form a wedge-shaped composite matrix, preferably by means of a pressure sensitive adhesive. The device operates by allowing the activating composiiton, e.g. an organic acid such as citric acid, to diffuse through the increasingly thicker composite matrix to continuously contact the indicating composition, e.g. an acid-base dye indicator such as 2,2',4,4',4",-pentamethoxy triphenylmethanol, to produce a visually observable color change at the temperature being monitored. The color change appears as a moving boundary at the color/non-color interface which moves transversely along the length of the device toward the thicker end of the composite matrix.