Constantan Wire??

[SMUGangsta]

Just been raking through my parts bins and found a couple of rolls of silver wire marked 'Constantan' - i was looking for nichrome (sp?) the heating element stuff.

Anyway - what is this constantan stuff and what is it used for?

i googled it and it appears to be a copper/nickel alloy for strain testing, but i dont understand how it would be used.

any suggestions on what and how to use it?

thanks

 

[Mikebits]

Dunno, but we use nichrome wire in our chem lab because it dose not heat up and give color during flame testing of other metal salt compounds... Not sure why I bothered to mention that. Bored I guess.

 

[Leftyretro]

Just been raking through my parts bins and found a couple of rolls of silver wire marked 'Constantan' - i was looking for nichrome (sp?) the heating element stuff.

Anyway - what is this constantan stuff and what is it used for?

i googled it and it appears to be a copper/nickel alloy for strain testing, but i dont understand how it would be used.

any suggestions on what and how to use it?

thanks

"Anyway - what is this constantan stuff and what is it used for?"

The main use for constantan wire I'm familiar with is as the negative lead for a J type thermocouple, Iron wire is used for the positive lead.

Lefty

 

[saturn1bguy]

Anyway - what is this constantan stuff and what is it used for?

Constantan wire has a TEMPCO (temperature coefficient) of zero, meaning its DC resistance doesn't change with temperature, which cannot be said of most any other electrical conductor.

 

[Mikebits]

Constantan wire has a TEMPCO (temperature coefficient) of zero, meaning its DC resistance doesn't change with temperature, which cannot be said of most any other electrical conductor.

Wow, did not know that. Makes sense though, Constantan as in constant. It just goes to show ya, never to old to learn something

I can't imagine what material would have 0 temp coeff. All metals react to temp don't they? I will have to look that one up... Not to imply I don't believe rather, I wish to know more.

 

[saturn1bguy]

I can't imagine what material would have 0 temp coeff.

Hey Mike,

Well, it's not *really* zero, but just so low that's it's as good as it gets as far as metals go.

EDIT: I bet zero isn't even zero if you go to enough decimal places

 

[Mikebits]

Thanks SBG, glad to see your back. You left us for awhile

 

[saturn1bguy]

Thanks SBG, glad to see you're back.

Thanks.

I poke around when I can...

 

[Mikebits]

I plan on making a trip to your area soon, I want to visit the Bryce canyons during my next break, maybe do a little ski time too