Abstract: An immersion heater for a fluidized bed decarbonation reactor includes an elongate cylindrical graphite heating element within a sealed chamber into which an inert gas, such as argon, is introduced for protecting the heating element from oxidation and from which the gas may be removed. The chamber is defined by a refractory metal sheath with longitudinal corrugations and externally covered by a protective layer formed by chromaluminization. An insulating refractory metal ring centers and holds the heating element within the sheath to prevent short circuits between the heating elements and the sheath. A composite metal plate holds the heating element and includes input and output electrical supply bars for providing power to the heater.

Abstract: An automatic rain gauge or pluviometer comprising a first receiver for receiving dry fallout; a second receiver for receiving wet fallout, provided with a first sensor able to emit a signal when a certain wet fallout sample volume has been collected; a closing device permitting the alternating closure of the two receivers as a function of a signal emitted by a precipitation detector; a measuring device located at the outlet of the second receiver and used for carrying out measurements of physicochemical quantities on the sample; a sampling device located at an outlet of the measuring device and used for arranging and keeping at a temperature below 0.degree. C. a fraction of each sample collected; and a checking system used for automatically controlling the aforementioned components as a function of the signals emitted by the sensors, including the first sensor and the precipitation detector and for managing the measurements performed on the sample.