After the 2021 revision of ISO 8529-1, discontinuation left only ²⁵²Cf and 241AmBe as standard reference fields [1]. Currently, the cost of one gram of ²⁵²Cf is approximately 27 million dollars, rendering it prohibitively expensive for widespread use compared to ²⁴¹AmBe, which is readily available, cost-effective, and has a long half-life [2]. This work describes the development of a system utilizing a ²⁴¹AmBe neutron source moderated within a lead cylinder to simulate the characteristics of a ²⁵²Cf field. This new setup will be instrumental for sample testing, calibrations, and irradiations required by the laboratory's demands. Study and characterize a lead-moderated neutron field, representing practical neutron fields relevant to neutron metrology, thereby expanding the measurement capabilities of the Neutron Metrology Laboratory (LNMRI/LN). To characterize the neutron field, a Bonner Multisphere Spectrometer (BMS) [3] was utilized. A neutron detector (LiI) was positioned at the center of polyethylene spheres with diameters of: 5.08 cm (2”), 7.62 cm (3”), 12.70 cm (5”), 20.32 cm (8”), 25.40 cm (10”), and 30.48 cm (12”). Measurements were conducted at a distance of 100 cm from both the ²⁵²Cf source (120 µg) and the system containing the ²⁴¹AmBe source (592 GBq) within the lead cylinder (Pb). Using the NeuraLN software, which employs neural network methods, values for parameters such as average energy and personal and environmental dose equivalents were obtained [4,5]. Comparing the experimentally obtained spectra, it is observed that the system utilizing ²⁴¹AmBe moderated by lead exhibits the intended characteristics of the ²⁵²Cf source. Other parameters also exhibit values similar to those of the ²⁵²Cf source. The measurements indicate that obtaining parameters similar to those of 252Cf is feasible, providing a viable option for use in the laboratory, aligned with the reference fields in which it operates.