The effects of atmospheric parameters (pressure, temperature, relative humidity, and wind) on the induced corona current through a corona probe are evaluated through a laboratory investigation. The corona probe has a high series resistence, which tends to linearize the relationship between the induced corona current and the electric field. From a best fit of the data, the slope of the linear relationship for corona currents greater than 1.5 μA varies with air density D as (D0/D)0.15. For lower currents the slope varies as (D0/D)0.33. The onset electric field required to initiate corona varies slightly with air density; this relationship is (D/D0)0.15. The high series resistance significantly reduces the effects of variations in the relative humidity and in low wind velocities across the corona point. When balloon borne, the probe can reliably measure thunderstorm electric fields.