Ensuring nonproliferation of, and safeguards for, special nuclear material (SNM) is critical for advancing the nuclear fuel cycle. However, the high-radiation, high-temperature, and highly corrosive environments associated with SNM present challenges to traditional measurement systems; which rely on sensitive electronics, optics, and structural integrity. To address this challenge, a dynamic single bubbler (DSB) method was explored; using a single dip tube with a linear actuator to estimate liquid density, and gas–liquid and liquid–liquid interface levels. This method employs linear regression of the data to reduce uncertainties and improve accuracy. The DSB method achieved density estimate uncertainties of less than 0.5% and surface level uncertainties under 0.5% across various fluids, including water, acetone, methanol, mineral oil, glycerol, and aqueous salt solutions. Results indicate that the DSB method provides accurate and robust estimates, with minimal maintenance and without the need for calibration. Furthermore, its applicability to immiscible liquids and various dip-tube geometries suggest potential widespread use in nuclear and other industrial applications where harsh conditions impede traditional approaches.