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fluke thermocouple connector question

updated sun 7 oct 07

 

Alisha Clarke on fri 5 oct 07


I bought a Fluke 51II from eBay, and bought a thermocouple and probe shield
from Axner. The thermocouple comes with a screw terminal, and I need to
connect a Fluke mini connector to it. A potter from the PotteryBasics group
pointed me to omega.com, where I probably should have bought the
thermocouple in the first place to save some money and get one with the
mini-connector already.

All of this got me thinking, however: Does anyone know long the wires from
the thermocouple to the Fluke can be? My gas kiln is about 15 ft from my
studio (outside). It would be convenient if I could have the Fluke inside
where I could monitor the kiln while working on other things, saving some
time going in and out. I would probably need about a 20-25 ft. wire from the
thermocouple to the Fluke. Will this work? What type of wire should be used?
Alisha

--
~~~~~~~~~~~~~~~~~~~~~~~~~
Alisha Clarke
www.alishaclarke.com
www.potterybasics.com

Bruce Girrell on fri 5 oct 07


Alisha Clarke asked:

> Does anyone know long the wires from the thermocouple to the Fluke can be?
> What type of wire should be used?

I spoke to a Fluke rep when I bought my 54-2. The quick answer is that the
length of the wire does not matter. The meter draws essentially no current
through the wires and therefore the resistance of the wire is unimportant.

The wire must be designed for use with your thermocouple and you must
connect the proper wire to the proper terminal. If you use a wire that is a
different metal from that used in the thermocouple or if you connect the
wires backward, then you create additional thermocouples at the junctions of
the wires. Chances are you're using a K thermocouple. Marc Ward at Ward
Burner (www.wardburner.com) can get you set with the proper connectors and
wire.

Bruce Girrell

Taylor Hendrix on fri 5 oct 07


If you get the true thermocouple extension wire it is going to be a
little money for that 20 to 25 feet, so be warned. You might need to
buy shielded thermocouple wire for that length, but I don't know your
specifics. Check the Fluke literature to see maximum length of probe.

You need to buy thermocouple extension wire that matches the
thermocouple you are using. That website should have it for sale. I do
believe the outer sheathing will be brown for the cheaper K
thermocouple. Each wire inside that will be color coded for the two
wires inside. Don't forget that the two wires are different types of
metal so you need to connect like wire to like leg of thermocouple.
That color coding should help. Once you get things put together check
room temp with your meter and if it reads funky, you may have switched
the leads.

I don't think I saw high temp thermocouples I liked at Omega or they
were out the last time I checked. I happened to have the low temp K
thermocouple that came with my Fluke so I just snipped off the welded
end of the probe and used the two resultant wires to extend my Axner
purchased K thermocouple. It works fine and the mini connector was
already attached.

If you have to attach your mini connectors to the wire you buy as
well, that's twice the carefulness you need, okay. Good stuff.

On 10/5/07, Alisha Clarke wrote:
...
> > All of this got me thinking, however: Does anyone know long the wires from
> the thermocouple to the Fluke can be? My gas kiln is about 15 ft from my
> studio (outside). It would be convenient if I could have the Fluke inside
> where I could monitor the kiln while working on other things, saving some
> time going in and out. I would probably need about a 20-25 ft. wire from the
> thermocouple to the Fluke. Will this work? What type of wire should be used?
> Alisha
....

Jim Willett on sat 6 oct 07


On Fri, 5 Oct 2007 07:25:57 -0400, Alisha Clarke
wrote:

>All of this got me thinking, however: Does anyone know long the wires from
>the thermocouple to the Fluke can be? My gas kiln is about 15 ft from my
>studio (outside). It would be convenient if I could have the Fluke inside
>where I could monitor the kiln while working on other things, saving some
>time going in and out. I would probably need about a 20-25 ft. wire from
the
>thermocouple to the Fluke. Will this work? What type of wire should be
used?
>Alisha
>
>--
>~~~~~~~~~~~~~~~~~~~~~~~~~
>Alisha Clarke
>www.alishaclarke.com
>www.potterybasics.com
>
Alisha,
There has been some good info posted already. If you know someone who
can silver solder, once you have determined you have the right wires
connected and twisted together, silver solder the connections. This will
guarantee your readings stay true. And the length you propose is
definitely no problem. I was an instrument mechanic in mining for years
and we ran thermocouple leads very long distances and read them with
portable meters such as yours.

Jim Willett
Out of the Fire Studio
http://www.outofthefirestudio.com

Alisha Clarke on sat 6 oct 07


Thanks Bruce, Taylor, Jim and John Sankey,
You've all given me the information I need. Apparently, I do need to buy the
specific thermocouple wire which is a bit expensive, but it will do the
trick. I appreciate the information from all of you!
Alisha


On 10/6/07, Jim Willett wrote:
>
> On Fri, 5 Oct 2007 07:25:57 -0400, Alisha Clarke
> wrote:
>
> >All of this got me thinking, however: Does anyone know long the wires
> from
> >the thermocouple to the Fluke can be? My gas kiln is about 15 ft from my
> >studio (outside). It would be convenient if I could have the Fluke inside
> >where I could monitor the kiln while working on other things, saving some
> >time going in and out. I would probably need about a 20-25 ft. wire from
> the
> >thermocouple to the Fluke. Will this work? What type of wire should be
> used?
> >Alisha
> >
> >--
> >~~~~~~~~~~~~~~~~~~~~~~~~~
> >Alisha Clarke
> >www.alishaclarke.com
> >www.potterybasics.com
> >
> Alisha,
> There has been some good info posted already. If you know someone who
> can silver solder, once you have determined you have the right wires
> connected and twisted together, silver solder the connections. This will
> guarantee your readings stay true. And the length you propose is
> definitely no problem. I was an instrument mechanic in mining for years
> and we ran thermocouple leads very long distances and read them with
> portable meters such as yours.
>
> Jim Willett
> Out of the Fire Studio
> http://www.outofthefirestudio.com
>



--
~~~~~~~~~~~~~~~~~~~~~~~~~
Alisha Clarke
www.alishaclarke.com