Abstract: To effectively evaluate the operational status of electric thrusters, Faraday probes and retarding potential analyzers used for plume diagnostics require regular calibration that relies on a stable and controllable plasma environment. For this purpose, the potential of a three-grid radio-frequency ion source to serve as a standard plasma generator was evaluated. Through systematic experiments, the relationship between grid voltage and ion energy was established, the correlations among radio-frequency power, gas flow rate, and ion current density were revealed, and the stability of the plasma emission intensity under various operating conditions was quantified using spectroscopic diagnostics. The results show that the beam generated by the ion source exhibits a stability better than 1.8% and demonstrates good repeatability, indicating that the ion source can serve as a standard plasma generator for comparative calibration of probes.