The NuCarb Automated Carbonate Preparation Device is a compact, bench-top system designed for the automated preparation of carbonate samples for high-precision stable isotope analysis. It is specifically engineered to provide highly precise and sensitive measurements of carbon (C) and oxygen (O) isotopes in carbonate minerals, making it an indispensable tool in isotope geochemistry and related fields. This device offers high-precision δ13C and δ18O isotope ratio determinations, particularly on small carbonate samples. It is seamlessly interfaced with the Nu Instruments Perspective Stable Isotope Ratio Mass Spectrometer, forming a powerful analytical platform. The NuCarb features a capacity for 50 individual sample vials, significantly enhancing sample throughput. Its automated process includes a motor-driven syringe for precise acid delivery (1-250µl) to each vial and a slow pump mechanism that prevents sample disturbance during pump-out. All internal components are maintained at a consistent 70°C to ensure optimal reaction conditions. The system utilizes acid digestion of carbonates to liberate CO2, which is then dried using a cryogenic water trap (at 90°C) and further purified by an adsorption trap (at -30°C). This adsorption trap is fully software-controlled, allowing for automated baking and cooling. The NuCarb can react samples typically ranging from 0.25 to 0.5 mg of pure CaCO3, and when coupled with the Perspective IRMS, it is capable of measuring samples as small as 20 µg for stable isotopes with a standard error below 0.01‰, making it suitable for ultra-small carbonate analysis. The NuCarb is ideal for a wide array of applications requiring precise and accurate measurements of C and O isotopes in carbonate minerals. It is extensively used in geological, paleoclimate, and environmental studies, including the analysis of δ13C and δ18O in carbonate samples as small as <5µg. Furthermore, it supports advanced applications such as clumped isotope analysis (d47, D47) for various carbonate forms, including calcite, aragonite, and dolomite. Its automated nature and individual reaction vials eliminate potential memory effects, ensuring reliable and reproducible results, which is crucial for high-throughput analysis. Additional features include an optical vial detection system and a substantial phosphoric acid reservoir capacity of 40ml, sufficient for approximately 400 samples (at 100µl acid per sample). An optional automated reference gas refill system further streamlines operations. The NuCarb runs under the Nu Instruments Perspective Stable Gas Control Software, providing integrated control and data management. Its design, which involves adding acid to individual reaction vessels, is similar to that of the Thermo Fisher Kiel device, highlighting its robust and proven methodology. For clumped isotope analysis, it can be operated in "Bellows mode" (3-4mg per replicate) or "Coldfinger mode" (280-400µg per replicate), offering flexibility based on sample availability and desired precision.