The present invention relates to processes for preparing a stable sol of medicament and hydrofluorocarbon, and for preparing medicament delivery devices containing said sol. The silicon carbide porous body is formed or machined into a convexly bowed shape, and after infiltration with the metal containing aluminum as the main component, the aluminum alloy layer on the radiation plane is further machined to form the bow shape. In addition, a storage device is manufactured by using such a spin valve element. The unique unitized electrical resistance measurement probe is also temperature stabilized using thermally bridged and balanced metallic elements; the first reference element being coated with an impermeable insulating coating, the second, the sacrificial corroding element, being fully exposed to the corrosive fluid medium.