Is a voltmeter an electric field meter? Silly question, but could have industry wide ramifications

K

KidFishJack

Member
Location
Kansas
Occupation
Streetlight safety inspector
Was not sure if this question should be posted under General Forum, Safety Forum, or Troubleshooting Forum...or is permitted at all.

First, we do not believe that a voltmeter, or the voltage function of a multimeter, is an electric field meter.

This question comes up as a company who uses electric field meters to find faults on streetlights, is asserting that using a volt/multimeter to troubleshoot lighting circuits encroaches on their service offerings. This isn't hypothetical- we are in the middle of this disagreement right now.

We understand reading the terms of this Forum, these questions cannot be used or construed as expert advice. However, we are hoping someone here could point us in the direction of any articles, technical papers, or demonstration devices/apparatus that can show the difference to a layperson.

Our concern isn't just for our livelihood, but for any electrician or electrical firm who works on street, parking lot and roadway lighting systems.

Thank you,

KFJ
 
Welcome to the forum.

Isn't this a contact vs non-contact distinction? In other words, if a voltmeter requires test-lead contact, how can it be considered an electric-field instrument?
 
By electric field meter do they mean something that measures the strength of a field, like in gauss, or a non-contact device that simply senses the presence of a field?

By the truest definition, any device that does not connect directly into the wiring works off of an "electric field'. Watch out for lawyer speak versus industry slang.
 
KidFishJack said:
This question comes up as a company who uses electric field meters to find faults on streetlights, is asserting that using a volt/multimeter to troubleshoot lighting circuits encroaches on their service offerings.
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Yeah, because I would believe an actual measurement with a meter and test leads over a non-contact voltage detector. And they know it! What's their accuracy rate?

-Hal
 
LarryFine said:
Welcome to the forum.

Isn't this a contact vs non-contact distinction? In other words, if a voltmeter requires test-lead contact, how can it be considered an electric-field instrument?
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Hi LarryFine

You are correct. That is why we do not understand their complaint. We are taking a physical measurement between two points...the known quantity of electricity on a streetlight and a secondary ground source. We do not fully know the particular electric field meter in use, but do know it cannot tell the user the actual voltage level on an object.
 
jim dungar said:
By electric field meter do they mean something that measures the strength of a field, like in gauss, or a non-contact device that simply senses the presence of a field?

By the truest definition, any device that does not connect directly into the wiring works off of an "electric field'. Watch out for lawyer speak versus industry slang.
Click to expand...
Hello Jim

Yes, they are measuring some sort of field, but do not know if it is the electric field or magnetic field. No contact at all by their device, we make contact.
 
Are they maybe talking about MV levels before a transformer? The mention of a secondary ground source is odd
 
hbiss said:
Yeah, because I would believe an actual measurement with a meter and test leads over a non-contact voltage detector. And they know it! What's their accuracy rate?

-Hal
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Hello Hal

No idea about their accuracy rate, but looking at a new IEEE publication on the subject, any 60Hz could be an interference source, such as overhead powerlines.
 
CoolWill said:
I'm going to pick this nit...

Electric fields don't have the units of gauss. Electric fields strength is volts/meter. Just sayin'.
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You are correct.
But the OP sounds like they didn't know what they are actually doing, that is why I asked if any clarifying words were used.
 
LarryFine said:
Sounds to me like they're trying to enforce a non-existent non-competition agreement.
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Bingo! They don't like you cutting into their work or second guessing them.
KidFishJack said:
Yes, they are measuring some sort of field, but do not know if it is the electric field or magnetic field. No contact at all by their device,
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Years ago, when I was climbing poles or even putting a ladder up against one, we had a "hot pole detector" that worked like that. We were to test every pole we wanted to climb. If it went off, we knew to stay away and put a sign on the pole saying "HOT POLE" for the next guy.

-Hal
 
CoolWill said:
I'm going to pick this nit...

Electric fields don't have the units of gauss. Electric fields strength is volts/meter. Just sayin'.
Click to expand...

A volt meter measures the voltage between two contact points. It doesn't measure electric field strength but rather the integral of the electric field between two points.

I would say electric field meter : voltmeter as speedometer : odometer
 
winnie said:
A volt meter measures the voltage between two contact points. It doesn't measure electric field strength but rather the integral of the electric field between two points.

I would say electric field meter : voltmeter as speedometer : odometer
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I'm strictly speaking of dimensional units. Volts per meter. Gauss is the CGS unit of magnetic flux density.
 
KidFishJack said:
This question comes up as a company who uses electric field meters to find faults on streetlights, is asserting that using a volt/multimeter to troubleshoot lighting circuits encroaches on their service offerings.
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If their service offering is to find faults (in any way), that could be so, but if it's specifically to use a "field meter" to find faults IMHO they're out of luck. Likewise that unless they have a contract that gives them an exclusive right, well, they don't have one.

There's another angle- @KidFishJack do you work for another contractor or for a municipality? Contractor vs contractor is a whole different matter from contractor vs city-that-owns-the-lights.

This really sounds like something for the lawyers to untangle, not the engineers.
 
KidFishJack said:
This question comes up as a company who uses electric field meters to find faults on streetlights, is asserting that using a volt/multimeter to troubleshoot lighting circuits encroaches on their service offerings. This isn't hypothetical- we are in the middle of this disagreement right now.
Click to expand...
As far as encroachment that is for the lawyers. But there is a safety concern potentially with one vs the other method of looking for a fault condition. Not sure the reason a fault is being looked for, there are many different sorts of faults that could be dangerous or even deadly. While a typical volt or multimeter will give a very accurate voltage reading vs the electrical field meter, the EFM will provide a safer test as it will allow to test for presence of electrical charge without direct contact with a potentially high voltage fixture. Now if the test is looking for a potential primary fault onto a street light it is even bigger safety issue to try to use a simple multimeter, with the potential to "blow up" the meter and severely injure the person doing the testing.
 
hbiss said:
Years ago, when I was climbing poles or even putting a ladder up against one, we had a "hot pole detector" that worked like that. We were to test every pole we wanted to climb. If it went off, we knew to stay away and put a sign on the pole saying "HOT POLE" for the next guy.

-Hal
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But not fix the problem?!? That's what I do when a customer has an energized piece of equipment from a fault that didn't clear, I just put a sign on it that says "live do not touch" problem solved 😂
 
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