- #1
Steven Ellet
- 85
- 3
How do I measure static electricity or is it even possible?
Steven Ellet said:How do I measure static electricity or is it even possible?
sophiecentaur said:There are different aspects of Static Electricity that are more, or less relevant, depending on the application. The actual Voltage can be relevant and so can the Charge. A Van de Graaf ball may be charged to several hundred kV but the charge is so small that it will do no more than give you a tickle. A big fat capacitor (100uF, for instance), charged to just a few hundred Volts could kill you. It's the total Energy stored that counts - along with the level of the Volts, which govern how much current (rate of discharge) will pass through you (or your delicate electronic equipment).
Steven Ellet said:I found this here: wikipedia.org/wiki/Electrometer
"An electrometer is an electrical instrument for measuring electric charge or electrical potential difference. There are many different types, ranging from historical handmade mechanical instruments to high-precision electronic devices. Modern electrometers based on vacuum tube or solid-state technology can be used to make voltage and charge measurements with very low leakage currents, down to 1 femtoampere. A simpler but related instrument, the electroscope, works on similar principles but only indicates the relative magnitudes of voltages or charges."
jim hardy said:okay, now search on "electrostatic voltmeter" and you should find lots of them for sale. Better companies will have a page explaining how they work.
http://www.trekinc.com/library/Tech_Notes.asp
sophiecentaur said:But what does he actually want to do with this information? Is he measuring static fields when he combs his hair or is it about lightning bolts?
sophiecentaur said:I'd rather not go into Water at this stage because the water analogy is not really useful except in terms of buckets with leaky holes in them and taps filling them up.
Suffice to say that a big object and in particular, a large plate, over Earth, will carry a large charge with a small Potential on it. If you have a small ball of, say 20cm diameter (Van de Graaf Ball), putting just a very few micro coulombs on it will raise its voltage to a very high value. That will spark across to you very easily but the spark will have very little charge - which corresponds to little energy in total. A capacitor with much less than 1mm between its plates and a total area of, dunno- say 1m squared, will store a lot of charge (maybe 1/100 Coulomb), even with just 400V across its terminals. So the Energy stored will be much much greater and, with the 400V will push that charge through you and give you a nasty shock.
But we would really need to know a bit more about the context of your question - or else there's no end to how much information we could be giving you and you will go into overload. Let's have some feedback.
I though of a (rather naff) water analogy - it's like comparing a single raindrop hitting you from a great height and a large tank of water landing on you, from just above your head.
A cylindrical water reservoir with radious tending to zero is similar to Van de Graaf ball, while a cylindrical water reservoir with radious tending to very large values is similar to a capacitor. When they discharge, the first water reservior doesn't cause much harm just as Van de Graaf ball.
jim hardy said:Something with polar molecules makes a better dielectric than free space.
Pure water is ~80X better but it's impractical to keep it pure..
hope i didn't just muddy the water.
Well, small Van de Graaff generator can deliver a slight shock too, but it is harmless.sophiecentaur said:A Van de Graaf ball may be charged to several hundred kV but the charge is so small that it will do no more than give you a tickle.
Static electricity is a type of electrical charge that is generated when two objects rub against each other, causing a transfer of electrons. It is called "static" because the charge remains in one place and does not flow like current electricity.
Static electricity can be measured using a device called an electroscope. This device uses a metal rod with a small metal ball at the top, and when the ball is charged, it will repel or attract other charged objects. The amount of repulsion or attraction can be used to measure the strength of the static charge.
The units of measurement for static electricity are volts and coulombs. Volts measure the difference in electrical potential between two points, while coulombs measure the amount of electrical charge. These units are used to quantify the strength of the static charge.
Measuring static electricity is important because it can help identify potential hazards in certain environments. For example, in industrial settings, a build-up of static electricity can lead to fires or explosions. By measuring the static charge, precautions can be taken to prevent these hazardous situations.
There are several ways to control or reduce static electricity, including using special materials that conduct electricity, such as copper or carbon, using grounding techniques to dissipate the charge, and using ionizers or humidifiers to neutralize the charge. The best method of control will depend on the specific environment and application of the static electricity.