An image data processing system and method are disclosed in which image data is organized for fast and efficient transfer of image data to and from an image memory using a tile cache. An efficient means for accommodating movements of the host facility, while maintaining riser top tension within the limits for long-term riser performance. When a frangible seal is broken, such as by application of pressure to the article, the chemical materials in the separate pouches come into contact with one another and may be mixed together. The thermal capacity of the fluid greatly exceeds that of the diaphragm, so that the temperature responsive characteristic of the temperature sensitive element accurately reflects the temperature of the pressurized fluid.