A relatively simple electric field mill has been developed by several high school students under the mentorship of personnel in the Severe Storms Research Center (SSRC) at the Georgia Tech Research Institute to study vertical electric fields in the atmosphere. Previous work demonstrated the ability of the students to design the device and compare its output with a commercial mill used at the SSRC. Recent work has focused on improvements to the mill circuitry, improved and simplified calibration procedures, and the production of multiple high school mills. Several of these mills have been used to establish a geometrical ‘enhancement' factor for both the commercial and high school field mills.