Vacuum pyrolysis allows to extend variety of sample material applicable Conventional Carbon dating. It simplify and shortened sample processing procedures. Reaction vessel (see scheme, below) is heart of carbide sample preparation in modern benzene line. It allows obtaining of lithium carbide by (1) melting of charcoal (C) and lithium alloy as it is used in conventional procedure, by (2) contacting of CO2 with molten lithium, by (3) contacting of carbonaceous gases produced during pyrolysis of sample material with lithium alloy, and some combination of above based on advantages operation in the one reaction vessel (4).