Formula for length of wire

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bobbyho

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I was given a formula before for figuring the length of wire on a spool (single conductor spool). It involved using an analog ohm meter and the formula. Does anyone know this? It would sure beat guessing or running a tape around the spool and counting the wires for a guess.
 
Re: Formula for length of wire

Well, I don't know the formula, but if you measure the resistance value of the wire, and then look up the resistance per foot of that particular size, you can probably get a good estimate.

I think we're being spoiled nowadays. Alot of wire is coming on "smart spools" now. :cool:
 
Re: Formula for length of wire

I don't think it is that simple...temperature would have an effect on measurement and how to you calibrate the device? What whould you use as a benchmark?

The folks at Greenlee have answered these questions with the 36186:
:)

In the meantime, here is a link to the GreenLee site: 36186
 
Re: Formula for length of wire

Doh...yup, forgot about the temperature. :eek: I do now recall a formula but it only takes into account the dimensions of the reel itself.

Well, how much does that gizmo cost? I saw a Harris model at the supplier for about $300.
 
Re: Formula for length of wire

Originally posted by peter d:


Well, how much does that gizmo cost?
Click to expand...
Originally posted by celtic:
I should be seeing that particular EC tom'row...I'll ask if he still has that tool in the arsenal and what the cost was :)

Click to expand...
 
Re: Formula for length of wire

It's real hard to measure such small resistances accurately. The temperature of the meter's even gonna change things.

Here's my thinking:

You probably only want to find out how much wire's on that spool because it's pretty close to maybe being less than you'll need for something.

Using a meter you still only have an approximation and the tolerance of the value you get is probably larger than the amount of error you can accept to know if there's enough wire.

And the larger and more expensive the wire, the lower the accuracy.

This is a perfect idea for the military.

Expensive, unreliable information.
 
Re: Formula for length of wire

You might be better off using a scale to weigh the spool. Perhaps you could weigh a full spool and even an empty one and do your calculations that way. You can get a postal scale at Office Depot for about $70 which is accurate to 0.01 pounds. Or you could go to the Post Office or even your friendly supermarket.
Another approach would be to count the number of strands or loops in each layer and do some calculations.
~Peter
 
Re: Formula for length of wire

That above gizmo is great for finding shorts in a wire. It will tell you how long the wire is and all you have to do is cut it in half then trace the wire to that point. :D
 
Re: Formula for length of wire

I don't have the formula you are talking about, but I have used this one:

Length of coiled wire =
Diameter of coil(average) x Number of coils x pie.

Hope that helps, if not please keep the pie as a gift.........
 
Re: Formula for length of wire

That's probably the best method.

Length of coiled wire =
Diameter of coil(average) x Number of coils x pie.
Click to expand...
Although I spell pi without the e :D
 
Re: Formula for length of wire

Alright, I don't wan...... ice cream does sound pretty good. :D
 
Re: Formula for length of wire

Ma teecher once tried to cornvince me that pie are squared. I says it aint so. Pie are round. Cornbread are square! :D :D
 
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