Dry Electric Field Mapping Apparatus

This is an excellent high school group project. Plot an electric field around electrodes of various configurations. Draw the electrodes in electrically conductive ink on semiconducting paper and transcribe your data on graph paper. Includes: cork board cover; 25 sheets black conductive paper with 20 x 25 cm grid; 100 sheets white paper with 20 x 25 cm grid; template; conductive ink pen; 4 alligator clip leads; instructions. Pen has a shelf-life of 6 months after opening.
Requires 12 V power supply or battery and a digital voltmeter, not included.