1. All readings read zero.
2. Separate spheres at max distance.
3. Turn on power supply and turn knob slowly clockwise to exactly 6kV. The probe is now charged.
4. Charge both spheres.
5. Turn knob of power supply counterclockwise to 0kV and then turn off power supply.
6. Bring spheres at desired distance. Try 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 cm.
7. Balance back the freely rotating sphere (align triangle with the fixed line) and measure the angle.
8. Separate spheres at max distance.
9. Discharge spheres by touching them with the probe and zero the knob (that measures angles).
10. Repeat all steps.