Low level electrical exposure

[winnie]

Why would a body of water produce current? Would it be AC or DC, how much current, would it be micro amps or smaller?

Again you have the physics issue here. When you are talking about a small portion of a large conductor, you need to describe current density, eg amps per square meter.

The body of water would not produce current. However current may flow through it.

There are numerous possible sources for this current flow, both natural and artificial.

Because the electrical power distribution network is grounded, it probably causes some amount of 60Hz current to flow through the Earth, including any bodies of water on the earth.

Conductors in a changing magnetic field will show current flow. Since the Earth's magnetic field is not constant, there will be minute current flows caused by this. During a geomagnetic storm, there can be measurable voltages induced in large loops of wire, caused by the changing magnetic field.

The wind, blowing naturally charged particles, can cause charge imbalance across the Earth's surface. This charge imbalance causes current flow as opposite charges attempt to recombine.

Etc. Etc.

We are talking about very low levels of current flow. I would be surprised if they reached mA per square meter without a local and identifiable source. At the same time, there is electricity all around us; we are composed of charged particles, and thus with a sensitive enough instrument, I am sure that current flow could be detected in any body of water. I cannot find a reference for expected currents in water itself, but _atmospheric_ current to ground is something on the order of picoamps per square meter, presumably part of the cycle that gets discharged with lightning. I do not know the details.

-Jon

 

[realolman]

Except for me, brain waves can be measured. Heart electrical activity.

You should be much more concerned with your lack of attention around live circuits.

BTW I did not intend to make light of your question... but I figured no one was going to respond. The lack of sense comment was meant to be self depricating toward me... a feeble attempt at humor.

 

[fallettap]

Again you have the physics issue here. When you are talking about a small portion of a large conductor, you need to describe current density, eg amps per square meter.

The body of water would not produce current. However current may flow through it.

There are numerous possible sources for this current flow, both natural and artificial.

Because the electrical power distribution network is grounded, it probably causes some amount of 60Hz current to flow through the Earth, including any bodies of water on the earth.

Conductors in a changing magnetic field will show current flow. Since the Earth's magnetic field is not constant, there will be minute current flows caused by this. During a geomagnetic storm, there can be measurable voltages induced in large loops of wire, caused by the changing magnetic field.

The wind, blowing naturally charged particles, can cause charge imbalance across the Earth's surface. This charge imbalance causes current flow as opposite charges attempt to recombine.

Etc. Etc.

We are talking about very low levels of current flow. I would be surprised if they reached mA per square meter without a local and identifiable source. At the same time, there is electricity all around us; we are composed of charged particles, and thus with a sensitive enough instrument, I am sure that current flow could be detected in any body of water. I cannot find a reference for expected currents in water itself, but _atmospheric_ current to ground is something on the order of picoamps per square meter, presumably part of the cycle that gets discharged with lightning. I do not know the details.

-Jon

Winnie,

Thank you, I am trying to put my volt meter experience in perspective, do you think that I received current through my body in every day life similiar to what I did with the meter like swimming for example or walking bear foot under power lines.

 

[winnie]

Thank you, I am trying to put my volt meter experience in perspective, do you think that I received current through my body in every day life similiar to what I did with the meter like swimming for example or walking bear foot under power lines.

realolman mentions brainwaves. Your body produces its own electric currents.

We can estimate the impedance of the circuit that you were a part of. My guess is that the current in question was limited by the meter's impedance (1 MOhm) and your body to ground capacitance (5-50MOhm, depending upon who's model of body capacitance you use) and that direct galvanic conduction through the building materials to ground was not significant.

Based upon this I estimate a current of about 10 micro-amps.

This is about the same as the current produce by a _single_ nerve fiber in your own body, at the peak of a nerve impulse.
http://www.vanderbilt.edu/lsp/abstracts/wikswo-s-1980.htm

-Jon

 

[jim dungar]

Based upon this I estimate a current of about 10 micro-amps.

This seems high, is this estimate based on the 3V meter reading?

 

[fallettap]

This seems high, is this estimate based on the 3V meter reading?

I plug in 3 volts with 150 mega ohms of resistance in an Ohms law calculator and come out to .000002 amps. What is the term for that measurement, pico amps.

 

[fallettap]

realolman mentions brainwaves. Your body produces its own electric currents.

We can estimate the impedance of the circuit that you were a part of. My guess is that the current in question was limited by the meter's impedance (1 MOhm) and your body to ground capacitance (5-50MOhm, depending upon who's model of body capacitance you use) and that direct galvanic conduction through the building materials to ground was not significant.

Based upon this I estimate a current of about 10 micro-amps.

This is about the same as the current produce by a _single_ nerve fiber in your own body, at the peak of a nerve impulse.
http://www.vanderbilt.edu/lsp/abstracts/wikswo-s-1980.htm

-Jon

I dont quite understand the article, does it mean the nerve goes to that level when your body is excited. What gets the nerve fiber to the the peak impulse?

 

[winnie]

This seems high, is this estimate based on the 3V meter reading?

I based my estimate on the meter impedance in series with the impedance of a 250 pF capacitor. The 250pF capacitor is an estimate of the human body capacitance used for ESD work. At 60Hz a 250 pF capacitor has an impedance of about 10 MegOhms. So I took the 120V and divided by 10Meg.

You mention an estimate from the 3V reading...this might be a better way to go. Assuming that the meter has a resistive impedance of 1 megohm, than to show 3V it needs to pass a current of 3uA. Of course this estimate is only as good as the meter's impedance rating.

I dont quite understand the article, does it mean the nerve goes to that level when your body is excited. What gets the nerve fiber to the the peak impulse?

Your nerves _function_ electrically. Rather than electron current flow they use ion current flow, but this is still a net motion of charge and thus an electric current.

You have many nerves in your body.

When a nerve is stimulated (for whatever that nerve happens to be sensitive to) it sends out 'impulses'. Very approximately, the _rate_ of these impulses depends upon the intensity of the stimulus. You touch a warm surface, and nerves in your skin will start sending impulses. You touch a hot surface, more impulses.

The paper that I referenced simply says that the peak current flow during a single impulse is about 10uA.

-Jon

 

[realolman]

You got 2 micro amps there, falletap... You sure there isn't a little pulling of the collective leggage here, falletap?

 

[tomP]

You got 2 micro amps there, falletap... You sure there isn't a little pulling of the collective leggage here, falletap?

realolman,
I think you are pretty close on the pulling of the leggage.
A government contractor doing electricial work asking those questions?

 

[fallettap]

realolman,
I think you are pretty close on the pulling of the leggage.
A government contractor doing electricial work asking those questions?

Last question if you have a 110 source and your ground is poor does the level of voltage drop to the ground source or is it still 110.

 

[barbeer]

If I read the poorly worded question right.........Exactly the opposite of what you are saying will usually happen, the voltage will spike.

 

[fallettap]

Can someone tell me what the measurement is called for .000003 in amps. Would thet be nano or pico amps. What is the techinical term (IE micro amps/milla amps etc).

Thanks Paul

 

[charlie b]

Can someone tell me what the measurement is called for .000003 in amps.

That would be 3 microamps. A "milli" is one thousandth. A "micro" is a millionth. A "nano" is one billionth. A "pico" is one trillionth.

 

[coulter]

fallettap -

You keep saying "110". You even talk about a meter reading "110". Are you in Europe? It would be very strange indeed to poke a meter into a receptacle in the US and get it to read 110.

carl

 

[fallettap]

That would be 3 microamps. A "milli" is one thousandth. A "micro" is a millionth. A "nano" is one billionth. A "pico" is one trillionth.

But it is 6 decimal places 1/1000 would be .0001 Micro would be .00001 so wouldnt it be a nano at .000001.

 

[fallettap]

fallettap -

You keep saying "110". You even talk about a meter reading "110". Are you in Europe? It would be very strange indeed to poke a meter into a receptacle in the US and get it to read 110.

carl

When plugged into the hot and nuetral outlet it shows 120V. When it touched me it was 3 volts.

 

[480sparky]

But it is 6 decimal places 1/1000 would be .0001 Micro would be .00001 so wouldnt it be a nano at .000001.

Here's the list I use:

 

[busman]

But it is 6 decimal places 1/1000 would be .0001 Micro would be .00001 so wouldnt it be a nano at .000001.

1/1000 = .001

.001 amps = 1 milliamp = 1000 microamps

Do the math.

 

[pfalcon]

Close the thread

Close the thread

The OP is expressing things in a manner that demonstrates a distinct lack of electrical knowledge. This thread should close.

Improper use of testing equipment.
Lack of knowledge of voltage vs current.
Reference to urban legend [AC in swimming pools]
Lack of knowledge of SI prefixes.
Reference to ELF/EMF controversy.

This person should not be working on electrical circuits without direct supervision from a professional to whom he can direct his questions.