Static electricity is the product of an imbalance between positive and negative charges on the surface of an object. It can be visible, for example when you notice a spark after touching a metal door handle; however, a more complex procedure is required to physically measure it. When you learn how to measure static electricity, you are basically measuring the surface area of a particular object.
Steps
Method 1 of 2: Measuring the Static Charge of Different Materials
Step 1. Gather the materials
For this experiment you need a small copper plate, a ground connection, electrical wires (such as those to start the car engine) with alligator clips, a sheet of white paper, scissors, a ruler, a balloon, hair, a cotton shirt, a polyester shirt, a carpet and a ceramic tile. This experiment measures the relative amount of static electricity present on an object.
- You can buy the copper saucer online or at a hardware store for a relatively low price.
- Grounding and alligator clip cables are available at hardware stores or electronics stores.
Step 2. Connect the copper plate to ground using the electrical wire
Take one of the two ends with an alligator clip and attach it to the ground connection, the other end connects to the plate. It doesn't matter where you plug the terminals, just make sure you've grounded the copper object.
By touching the saucer with an object you can remove any residual charge present on the object itself
Step 3. Cut a sheet of paper into 100 pieces of 5x5mm
Take a ruler, draw 5mm squares on each side and cut them out. Committed to making "confetti" as similar to each other; if you have a cutter, you can get a much easier and more accurate job.
- Remove any static electricity from the pieces of paper by transferring them to the copper plate.
- After removing any electrostatic charge, transfer the paper to a flat tray for the next steps in the experiment.
Step 4. Inflate a balloon
Blow into it until it becomes a medium to large sphere; in reality, size is not very important as long as you use the same balloon for all materials. If it breaks during one of the tests, you need to inflate another one and start over to keep the experiment parameters constant.
Remove any residual electrostatic charge from the balloon by rolling it onto the copper plate
Step 5. Rub it five times on the surface of a material
First, choose the object whose electrostatic charge you want to measure; To start, you can use hair, carpet, a cotton shirt, a polyester shirt, and a ceramic tile.
Always rub the balloon in the same direction on the surface you have chosen
Step 6. Transfer the balloon over the pieces of paper
Friction with the material has transferred a variable amount of static electricity to it; consequently, when you hold it over the paper, the confetti adhere to the surface of the balloon and their number is directly proportional to the intensity of the accumulated electrostatic charge.
Don't roll the balloon over the pile of paper, just put it down and count the number of fragments
Step 7. Count and note the number of confetti remaining on the surface of the balloon
Detach them one by one by counting them; the various materials generate a different electric charge and consequently the number of fragments changes. Repeat the experiment with different objects to quantify those differences.
Remember to remove the static charge from the card before each repetition
Step 8. Compare the results
Observe the data collected and evaluate the number of confetti attracted by the balloon after rubbing it on the different materials; the greater the amount of paper fragments, the greater the electrostatic charge.
- Read the list and see which materials allowed the balloon to "catch" more squares; the hair has a lot of static electricity and is likely to be the "winners" of that experiment.
- Although this method does not provide a numerical data that exactly quantifies the electrostatic charge of an object, it does allow us to know the relative quantities based on the material.
Method 2 of 2: with a Handcrafted Electroscope
Step 1. Gather the materials
An electroscope is a device that detects static electricity using pieces of metal that separate in the presence of an electrical charge. You can build a very simple version of it using some common objects; you need a glass jar with a plastic lid, a sheet of aluminum foil and a drill.
Step 2. Make a tinfoil ball
Take a square piece of aluminum foil with 25 cm on each side; the exact size is not important, but it crumples the paper into a sphere. Make it as rounded as possible.
The ball should be about 5cm in diameter; however, even in this case, it is not a fundamental detail. Just avoid making a ball that is too small or too big
Step 3. Twist some aluminum foil to make a wand
Take another piece of the same material and shape it into a stick just a little shorter than the jar. The rod must hang from the bottom of the container for about 7-8 cm and stick out over the edge for about 10 cm.
Step 4. Connect the ball to the rod by wrapping both of them with more aluminum foil
Use a larger sheet of the same material to join and wrap the two elements; twist the wrapper around the wand to hold everything in place.
Step 5. Drill a hole in the plastic cap
Use the drill and drill through the center of the lid creating a hole large enough to insert the aluminum rod; if you don't have a drill available, you can use a nail and a hammer to achieve the same result.
Be careful when using the drill or hammer, a responsible adult is recommended at this stage
Step 6. Attach the ball-wand assembly to the lid
Slide the stick through the hole, taking care that the sphere remains on the outside of the lid; block everything with adhesive tape on the lower and upper face of the lid, at the end fold the last centimeter of the rod at 90 °.
Step 7. Cut out a triangle from a folded sheet of aluminum foil
Take a piece of size 15x7.5 cm and fold it lengthwise, so that it becomes a square with a side of 7.5 cm. Then cut out a triangle whose vertex almost reaches the folded edge; leave the two triangles obtained connected at this point and do not separate them. When finished, you should have two triangles connected to each other at the top through a small flap of aluminum foil.
If you make a mistake and cut the last flap, take a new aluminum foil and start over
Step 8. Hang the two triangles on the folded end of the bar
Arrange them so that they almost touch each other across the bar and screw the cap onto the jar. In this phase be careful not to drop the triangles that are just suspended; hold the electroscope vertically.
If the triangles fall out, unscrew the cap and put them back in place
Step 9. Watch the device in action
Rub the balloon into your hair and bring it close to the top of the tinfoil ball. You should notice the triangles moving away from each other. When the instrument comes into contact with static electricity, the two triangles are charged in opposite ways, repelling each other; when it does not detect any charge, the triangles remain in the rest position.
