How can an electroscope be used to measure dose rate from a radioactive source?

An electroscope can measure dose rate from a radioactive source by detecting the ionization of air caused by radiation. When the radioactive source emits radiation, it ionizes the air around it, allowing electrons to flow and discharge the electroscope. By observing the rate at which the electroscope discharges, one can estimate the dose rate, as a faster discharge indicates a higher radiation intensity. Calibration against known radiation sources is often necessary for accurate measurements.