A heating chamber (1) for a heating furnace is proposed, with which electrothermal vaporization of impurities from samples can be effected in order to be able to then analyze them spectrometrically. The heating chamber has a wall (3), a sample reception area (5), a nozzle area (7) and two electrical connection areas (9, 11). The heating chamber (1) is specially configured such that an electric current flows through the wall (3) in such a way that a heating capacity caused by it is higher in the nozzle area (7) than in the sample reception area (5). For example, the electrical connection areas (9, 11) may be arranged in a radial direction remoter from the longitudinal axis (8) than a part of the wall (3) surrounding the nozzle area (7), and the heating chamber (1) may be configured, for example by means of a locally constricted area (13), in such a way that the current between the two electrical connection areas (9, 11) is predominantly conducted radially inwards towards the part of the wall (3) surrounding the nozzle area (7). Advantageous heat distribution in the heating chamber (1) achievable thereby may have a positive effect on the analysis of sample impurities.

A heating chamber (1) for a heating furnace is proposed, with which electrothermal vaporization of impurities from samples can be effected in order to be able to then analyze them spectrometrically. The heating chamber has a wall (3), a sample reception area (5), a nozzle area (7) and two electrical connection areas (9, 11). The heating chamber (1) is specially configured such that an electric current flows through the wall (3) in such a way that a heating capacity caused by it is higher in the nozzle area (7) than in the sample reception area (5). For example, the electrical connection areas (9, 11) may be arranged in a radial direction remoter from the longitudinal axis (8) than a part of the wall (3) surrounding the nozzle area (7), and the heating chamber (1) may be configured, for example by means of a locally constricted area (13), in such a way that the current between the two electrical connection areas (9, 11) is predominantly conducted radially inwards towards the part of the wall (3) surrounding the nozzle area (7). Advantageous heat distribution in the heating chamber (1) achievable thereby may have a positive effect on the analysis of sample impurities.

A furnace for producing a graphite product and associated processes are provided. The furnace can include a furnace housing, an array of crucibles provided within the furnace housing and each having a crucible cavity for receiving a starting material, the crucibles being distributed longitudinally spaced-apart from one another with adjacent ones of the crucibles being distanced from one another to define a gap having a predetermined width therebetween, an electrically conductive packing medium received in the furnace housing to fill each of the gaps and to at least partially surround the crucibles, and first and second electrodes each partially extending into the electrically conductive packing medium. The predetermined width is such that upon passage of an electrical current from the first electrode to the second electrode, resistive heating is generated through both the electrically conductive packing medium and the crucible sidewalls to heat the starting material.