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Thermocouple wire

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Dennis Jones

Joined: 17 Sep 2006
Posts: 45
Location: Poplar Grove, IL

Posted: Tue Jun 17, 2008 10:03 am Post subject: Thermocouple wire

What is the function of "serving thermocouple  wire".

  

 Jonsey

   [quote][b]

nuckolls.bob(at)cox.net
Guest

Posted: Tue Jun 17, 2008 4:00 pm Post subject: Thermocouple wire

At 12:59 PM 6/17/2008 -0500, you wrote:

 	  Quote: 	
		  What is the function of "serving thermocouple wire".



Jonsey


	


   Your use of the word "serving" doesn't bring

   up an image for me. I think I've heard the term

   used but its meaning escapes me at the moment.



   Bob . . .

BobsV35B(at)aol.com
Guest

Posted: Tue Jun 17, 2008 4:14 pm Post subject: Thermocouple wire

Hmmmm!

  

 When on a sailboat, "serving" something means we wrap it in a protective  covering. Any possibilities there?

  

 Happy  Skies,



Old Bob

AKA

Bob Siegfried

Ancient Aviator

628 West  86th Street

Downers Grove, IL 60516

630 985-8502 

Stearman  N3977A

Brookeridge Air Park LL22

  

  In a message dated 6/17/2008 7:02:11 P.M. Central Daylight Time,  nuckolls.bob(at)cox.net writes:

  	  Quote: 	
		  -->    AeroElectric-List message posted by: "Robert L. Nuckolls, III"    <nuckolls.bob(at)cox.net>



At 12:59 PM 6/17/2008 -0500, you    wrote:

 	  Quote: 	
		  What is the function of "serving thermocouple    wire".



Jonsey


	


   Your use of the word    "serving" doesn't bring

   up an image for me. I think I've heard    the term

   used but its meaning escapes me at the    moment.



   Bob . .  .

	






Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.

  [quote][b]

paul.r.kuntz(at)gmail.com
Guest

Posted: Tue Jun 17, 2008 4:50 pm Post subject: Thermocouple wire

That's what I was thinking -- in nautical use, serving means to wrap a large line with a smaller line or with cloth to protect it from chafing.  So, when a wire is significantly longer than required, the excess is often folded back on itself a few times, then the end wrapped (served) around the folded portion to take up the extra length neatly.  In the case of thermocouple wire, the application would be to get rid of the slack in the wire without having to cut it and thereby introduce additional dissimilar material junctions in the middle of the wire.  Bob has talked many times about joining or splicing thermocouple wires so as not to influence the properties of its temperature detection ability, but I suspect the idea of "serving" the wire rather than remove the exess is another bit of electrical folklore that advises people to never cut and rejoin thermocouple cable.

   

 Cheers,

 Paul Kuntz



 

 On 6/17/08, BobsV35B(at)aol.com (BobsV35B(at)aol.com) <BobsV35B(at)aol.com (BobsV35B(at)aol.com)> wrote: [quote]  Hmmmm!

  

 When on a sailboat, "serving" something means we wrap it in a protective covering. Any possibilities there?

  

 Happy Skies,



Old Bob

AKA

Bob Siegfried

Ancient Aviator

628 West 86th Street

Downers Grove, IL 60516

630 985-8502 

Stearman N3977A

Brookeridge Air Park LL22

   

  In a message dated 6/17/2008 7:02:11 P.M. Central Daylight Time, nuckolls.bob(at)cox.net (nuckolls.bob(at)cox.net) writes:

  	  Quote: 	
		  --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net (nuckolls.bob(at)cox.net)>

 

At 12:59 PM 6/17/2008 -0500, you wrote:

 	  Quote: 	
		  What is the function of "serving thermocouple wire".



Jonsey


	


   Your use of the word "serving" doesn't bring

   up an image for me. I think I've heard the term

    used but its meaning escapes me at the moment.



   Bob . . .

	






   Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.

  	  Quote: 	
		  

	


[b]

mrspudandcompany(at)veriz
Guest

Posted: Tue Jun 17, 2008 5:08 pm Post subject: Thermocouple wire

Hi Jonsey,  

   

Can you please restate your question and give us some reference context??  

   

Roger  

   

--

bob(at)bob-white.com
Guest

Posted: Tue Jun 17, 2008 5:50 pm Post subject: Thermocouple wire

On Tue, 17 Jun 2008 20:11:44 EDT

BobsV35B(at)aol.com wrote:



 	  Quote: 	
		   Hmmmm!

  

 When on a sailboat, "serving" something means we wrap it in a protective  

 covering. Any possibilities there?

  

 Happy  Skies,

 

 Old Bob

 AKA

 Bob Siegfried

 Ancient Aviator

 628 West  86th Street

 Downers Grove, IL 60516

 630 985-8502 

 Stearman  N3977A

 Brookeridge Air Park LL22

 

 

 In a message dated 6/17/2008 7:02:11 P.M. Central Daylight Time,  

 nuckolls.bob(at)cox.net writes:

 

 

 <nuckolls.bob(at)cox.net>

 

 At 12:59 PM 6/17/2008 -0500, you  wrote:

 >What is the function of "serving thermocouple  wire".

 >

 >Jonsey

 

 Your use of the word  "serving" doesn't bring

 up an image for me. I think I've heard  the term

 used but its meaning escapes me at the  moment.

 

 Bob . .  .

 

 

 

 

 

Interestingly enough, the only result from Google for "serving
	


thermocouple wire" is to AC-21-99, Aircraft Wiring and Bonding



Section 2 Chapter 16, Figure 16-14 shows the procedure and seems to

match with the nautical terminology although I've don't recall hearing

it before in reference to wiring.

(http://www.casa.gov.au/rules/1998casr/021/021c99s2c16.pdf)



Bob W. (Hanging on to the "bitter end".)



Do not archive

-- 

N93BD - Rotary Powered BD-4 - http://www.bob-white.com

3.8 Hours Total Time and holding

Cables for your rotary installation - http://roblinstores.com/cables/

Dennis Jones

Joined: 17 Sep 2006
Posts: 45
Location: Poplar Grove, IL

Posted: Tue Jun 17, 2008 6:13 pm Post subject: Thermocouple wire

I found a reference in AC 21-99 that states that  the thermocouple wire is served at the branching point using nylon or waxed  cotton cord in cool areas and fiberglass cord in hot areas. It also shows  how to do the wrapping. It also references using clear lacquer at the  flat base area covering 12.7 mm. The serving will prevent unraveling of the  outer jacket.

  

 Jonsey

   [quote][b]

nuckolls.bob(at)cox.net
Guest

Posted: Tue Jun 17, 2008 7:21 pm Post subject: Thermocouple wire

At 09:10 PM 6/17/2008 -0500, you wrote:

 	  Quote: 	
		  I found a reference in AC 21-99 that states that the thermocouple wire is 

served at the branching point using nylon or waxed cotton cord in cool 

areas and fiberglass cord in hot areas. It also shows how to do the 

wrapping. It also references using clear lacquer at the flat base area 

covering 12.7 mm. The serving will prevent unraveling of the outer jacket.




	


   Aha! Yes, SOME thermocouple wires are covered in a woven

   fiberglas jacket and they will unravel with time and look

   funky. I have used the dacron flat lace to wrap the outer

   jacket and prevent fraying. You can use a short piece of

   heatshrink for this task too. As far as 'extra' wire, you

   can coil it up if you're loath to cut it. But I generally

   cut to finished length and put a connector on it.



   My favorite TC wires are the TT-K series from Omega found

   at:



http://www.omega.com/ppt/pptsc.asp?ref=XC_K_TC_WIRE&Nav=temh06



Neoflon

PFA

(HighPerformance)



20      TT-K-20         Solid

20      TT-K-20S        7 x 28

22      TT-K-22S        7 x 30

24      TT-K-24         Solid

24      TT-K-24S        7 x 32

30      TT-K-30††       Solid

36      TT-K-36††       Solid

40      TT-K-40††       Solid



  This is a Tefzel-like insulation that is easy to strip,

  reasonably robust and user friendly in the tiny (36 and 40AWG)

  wire sizes. This stuff won't unravel.



  Bob . . .

        ----------------------------------------)

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

        ----------------------------------------

nuckolls.bob(at)cox.net
Guest

Posted: Tue Jun 17, 2008 7:27 pm Post subject: Thermocouple wire

 	  Quote: 	
		   >

Interestingly enough, the only result from Google for "serving

thermocouple wire" is to AC-21-99, Aircraft Wiring and Bonding



Section 2 Chapter 16, Figure 16-14 shows the procedure and seems to

match with the nautical terminology although I've don't recall hearing

it before in reference to wiring.

(http://www.casa.gov.au/rules/1998casr/021/021c99s2c16.pdf)



Bob W. (Hanging on to the "bitter end".)


	


   Interesting. This is a rather dated document that touches on TC

   wiring techniques typical of 1930 to 1950 when self-powered

   TC temperature instruments were common. These tended to have

   large AWG wires of specific length that could not be

   altered without affecting calibration of the instrument.



   They also did not benefit from modern plastic insulations.



   Modern TC signal conditioners draw pico-amperes of Seebeck

   voltage, ANY gage wire of ANY length will produce satisfactory

   performance. Yeah kids, that's how our grandpas used to do

   it!



   Bob . . .

        ----------------------------------------)

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

        ----------------------------------------

jmcburney(at)pobox.com
Guest

Posted: Wed Jun 18, 2008 6:50 am Post subject: Thermocouple wire

Yes, WE did!



Do not archive

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