Electrolytic deposition apparatus (1; 101) for making an object comprising an alloy, said apparatus (1; 101) comprising: - means suited to contain an electrolytic solution comprising the elements of said alloy; - means comprising a frame for supporting at least a core suited to receive said elements being deposited thereon; - weighing means suited to weight said frame and said at least a core immersed in a weighing solution and suited to identify the total weight of said frame and said core immersed in said weighing solution; - a central control unit suited to control said apparatus; characterized in that it comprises means for measuring the density of said weighing solution at the time of weighing said frame and said core by means of said weighing means, and in that said central control unit is suited to receive said values of weight and density and to calculate the weight of a deposit (D1') deposited on said core during a step of electrolytic deposition as: D 1 ′ = P 1 − P 0 + Sa + d 0 sol − d 1 sol * V 0; wherein: - P0 and P1 represent the weighing values of the total weight of said frame and said core respectively at the beginning and at the end of said deposition step, Sa represents the error correction term due to the Archimedean buoyancy force and is calculated as: Sa = d 1 sol * ΔV 1 dep, wherein: - ΔV1dep is the value of the volume of the quantity of elements deposited during said step of electrolytic deposition; - d0sol and d1sol represent the values of the density of the electrolytic solution at the beginning and at the end of said step of electrolytic deposition and V0 represents the volume of said core, and in that said weighing solution coincides with said electrolytic solution. - means suited to contain an electrolytic solution comprising the elements of said alloy; - means comprising a frame for supporting at least a core suited to receive said elements being deposited thereon; - weighing means suited to weight said frame and said at least a core immersed in a weighing solution and suited to identify the total weight of said frame and said core immersed in said weighing solution; - a central control unit suited to control said apparatus; characterized in that it comprises means for measuring the density of said weighing solution at the time of weighing said frame and said core by means of said weighing means, and in that said central control unit is suited to receive said values of weight and density and to calculate the weight of a deposit (D1') deposited on said core during a step of electrolytic deposition as: D 1 ′ = P 1 − P 0 + Sa + d 0 sol − d 1 sol * V 0; wherein: - P0 and P1 represent the weighing values of the total weight of said frame and said core respectively at the beginning and at the end of said deposition step, Sa represents the error correction term due to the Archimedean buoyancy force and is calculated as: Sa = d 1 sol * ΔV 1 dep, wherein: - ΔV1dep is the value of the volume of the quantity of elements deposited during said step of electrolytic deposition; - d0sol and d1sol represent the values of the density of the electrolytic solution at the beginning and at the end of said step of electrolytic deposition and V0 represents the volume of said core, and in that said weighing solution coincides with said electrolytic solution.