An Electroscope is an apparatus that is used to detect electrostatic field, it shows in a visible way the presence of an electric charge, with one you can even have a quantitative idea about how strong is the field. The simple electroscope proposed here is constructed with minimum and common materials and in fact you can build one right now in your kitchen. Visit http://www.innovationview.com/vdg.html for Electrostatic Generator plans.
Step 1: Materials
You will need only a glass jar with plastic cap and Aluminum foil roll.
Step 2: Making an Aluminum Ball
Cut a square 10 x 10 of Aluminum foil and smash it in something resembling a ball
Step 3: Aluminum Rod
Take an Aluminum strip with 4 x 10 and smash in form of a rod with 4.
Step 4: Ball and Rod
The rod and the ball made with smashed Aluminum foil.
Step 5: Connecting Rod and Ball
Connect the ball with the rod wrapping a piece of Aluminum foil covering the ball and twisting the end over the rod.
Step 6: Drilling Plastic Cap
Take the plastic cap and make a centralized hole on it enough to the rod pass through, use a puncher or an electric drill.
Step 7: Mounting
Introduce the rod in the cap leaving the ball outside when the jar is covered.
Step 8: Bending the Rod
Make a 90° bend in the rod leaving a 1 long bended end.
Step 9: Preparing the Aluminum Leaf
Take a 10 strip of Aluminum foil and fold the extremities leaving it with the dimensions given in the figure.
Step 10: Mounting the Internal Structure
Connect the folded foil with the rod/ball conjunct by curving the bended end over the middle of it.
Step 11: Finalizing the Mountage
Close the jar with the cap and it are done.
Step 12: Testing the Electroscope
When the Electroscope top sphere is put near or contacting a charged body, like a Hand Powered VDG, the leafs will spread apart proportionally to charge intensity. More DIY plans at http://www.innovationview.com