The Great Bottle Opener Giveaway

Home Brew Forums > Home Brewing Beer > Electric Brewing > Thermocouple plug

Reply
 
LinkBack Thread Tools
Old 02-01-2013, 04:21 PM   #1
pentiumone133
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 58
Liked 5 Times on 3 Posts

Default Thermocouple plug

Hi. Building a RIMS system and I dont want to permenantly hard wire my thermocouple probe to the back of the PID. I know thermocouple wire is kind of special, but I have some bad thermocouples with wires still on them i can use as pigtails. My question is, if this wire is so special, would adding a male/female disconnect between the TC and the PID cause an issue? I was thinking a typical headphone panel mount jack on the PID side and a headphone jack solder plug on the TC side.

Thinking this
http://www.amazon.com/Rean-NYS231-3-...ref=pd_sim_e_1

and this

http://www.amazon.com/3-5mm-Stereo-P...d_bxgy_e_img_y

__________________
pentiumone133 is offline
 
Reply With Quote Quick reply to this message
Old 02-01-2013, 10:45 PM   #2
JRems
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2010
Location: Mahopac, NY
Posts: 2,227
Liked 57 Times on 49 Posts
Likes Given: 9

Default

You need a special connector when using a thermocouple. The headphone Jack most likely won't work

__________________
Quote:
Originally Posted by Bobby_M View Post
Simcoe smells like 10 cats pissing on a pine tree. It's awesome.
JRems is offline
 
Reply With Quote Quick reply to this message
Old 02-01-2013, 11:12 PM   #3
aquenne
Feedback Score: 0 reviews
Recipes 
 
Join Date: Oct 2011
Location: Paris, Ontario
Posts: 226
Liked 5 Times on 5 Posts
Likes Given: 6

Default

you should be very careful when extending/changing the wiring on a thermocouple.. it is very critical that both leads are of the exact same material, and of a known resistance (ie: if you add a switch or connection in between, you are changing the impedance).

RTD's are far more robust when it comes to what I think you woudl like to do.. your pid should support a PT100, and they are not that expensive.

__________________
aquenne is offline
 
Reply With Quote Quick reply to this message
Old 02-02-2013, 02:27 AM   #4
blaster_54738
BackDraught Brewing Co
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
blaster_54738's Avatar
Recipes 
 
Join Date: Jan 2012
Location: Eleva, WI
Posts: 372
Liked 36 Times on 32 Posts
Likes Given: 79

Default

Same question here. I will be ordering an Auber SYL-2352 and planned on using a K-type thermocouple but this would be a better option with the deluxe cable so it's removable?

http://www.auberins.com/index.php?ma...roducts_id=246

__________________
Primary EMPTY

Secondary EMTPY

Kegged Bourbon Barrel Milk Stout, Vanilla Porter

Bottled Skeeter Pee, Apfelwein

Coming Soon English Brown Ale, Double Chocolate Stout, Mojave Red

BackDraught Home Brewery
blaster_54738 is offline
 
Reply With Quote Quick reply to this message
Old 02-02-2013, 02:15 PM   #5
DougK
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
DougK's Avatar
Recipes 
 
Join Date: Jan 2013
Posts: 1,154
Liked 125 Times on 100 Posts
Likes Given: 1

Default

You don't have to worry about using a different material for splicing thermocouple wire provided the material being used is the same on both sides (for example, using a copper barrel splice) and the transition from thermocoiple wire to splice material and back again happens at the same temperature.

A thermocouple is actually just 2 dissimilar metals joined together. Any time you join 2 dissimilar metals, they will create a small electric current that is proportional to the temperature of the coupling.

What this means is when you transition the thermocouple wire to copper, you are creating one thermocouple and another on the transition back. If the same material is used , and the same temperature occurs at both junctions, they cancel each other out.

They make something called a uniform temperature reference which basically does this, only the transition back to thermocouple wire doesn't happen. This allows cheaper copper wire to be used instead of thermocouple wire when you have several temperature measurements in a single remote location.

Hope this helps

__________________

I'm not insane, my mother had me tested.

DougK is offline
 
Reply With Quote Quick reply to this message
Old 02-03-2013, 12:55 PM   #6
pentiumone133
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 58
Liked 5 Times on 3 Posts

Default

Quote:
Originally Posted by DougK View Post
You don't have to worry about using a different material for splicing thermocouple wire provided the material being used is the same on both sides (for example, using a copper barrel splice) and the transition from thermocoiple wire to splice material and back again happens at the same temperature.

A thermocouple is actually just 2 dissimilar metals joined together. Any time you join 2 dissimilar metals, they will create a small electric current that is proportional to the temperature of the coupling.

What this means is when you transition the thermocouple wire to copper, you are creating one thermocouple and another on the transition back. If the same material is used , and the same temperature occurs at both junctions, they cancel each other out.

They make something called a uniform temperature reference which basically does this, only the transition back to thermocouple wire doesn't happen. This allows cheaper copper wire to be used instead of thermocouple wire when you have several temperature measurements in a single remote location.

Hope this helps
Yes, it helps a lot. So based on what you have said I shouldn't have an issue removing the ends of the thermocouple, soldering onto a 3.5MM headphone jack, mating that with a female headphone jack, then running thermocouple wire from the solder side of the female jack back to the PID?

Is there any issue soldering the connections as it introduces another type of metal into the mix? I noticed that the lug connections on my thermocouples now are not soldered, but that could be because they are cheap chinese ones.
__________________
pentiumone133 is offline
 
Reply With Quote Quick reply to this message
Old 02-04-2013, 01:19 PM   #7
DougK
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
DougK's Avatar
Recipes 
 
Join Date: Jan 2013
Posts: 1,154
Liked 125 Times on 100 Posts
Likes Given: 1

Default

Quote:
Originally Posted by pentiumone133 View Post
Yes, it helps a lot. So based on what you have said I shouldn't have an issue removing the ends of the thermocouple, soldering onto a 3.5MM headphone jack, mating that with a female headphone jack, then running thermocouple wire from the solder side of the female jack back to the PID?

Is there any issue soldering the connections as it introduces another type of metal into the mix? I noticed that the lug connections on my thermocouples now are not soldered, but that could be because they are cheap chinese ones.
That is correct, provided you don't use a gold plated plug in a standard jack. The key here is the splice goes from thermocouple wire to splice wire and back to thermocouple.


Solder may introduce a bit of inaccuracy into the system, I'm actually not totally sure on that. When connecting wires at work, we always use either crimp connections or screw terminals. If you were soldering thermocouple wires together, it wouldn't affect it at all. Commercial thermocouple wire is often soldered or brazed at the junction to keep the wires together, but I am not sure how it would affect soldering thermocouple wire on to another metal. The study that I saw and in which I used to base my original post on was specifically looking at quick-connect pins and sockets. Is a special (much more expensive) pin/socket needed on a cannon connector, or will the standard work? It was found that provided the junctions happen at the same temperature, and most of the time they are when making a quick-connect, the temperature reading wasn't affected.


I'll have to look into this and get back to you.
__________________
DougK is offline
 
Reply With Quote Quick reply to this message
Old 02-04-2013, 03:41 PM   #8
jCOSbrew
HBT_SUPPORTER.png
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2012
Location: Colorado Springs, CO
Posts: 597
Liked 35 Times on 32 Posts
Likes Given: 7

Default

I used a headphone type disconnect for my RTD, cheap and effective.

Use the auberins or other RTD with the panel disconnect or use a TC without any disconnects for an accurate temp reading.

__________________
jCOSbrew is offline
 
Reply With Quote Quick reply to this message
Old 02-05-2013, 01:50 PM   #9
pentiumone133
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 58
Liked 5 Times on 3 Posts

Default

I was thinking about this more, and if the issue is different types of metals creating a reaction and throwing off the temperature then how is it possible to connect the thermocouple to the PID at all? The wires crimp onto lug connectors. These lugs, I assume, are standard lugs not made out of specific material. Then, the lugs are screwed onto metal screws on the PID, which, again I assume are not made out of specifica materials. THEN....inside the PID there is traces and connections on the boards before it actually gets to its final destination in the logic, right?

How does this work? Its the same concept as cutting the cable in the middle and soldering in a copper wire. The metal type changes two or three times already between the sensor itself and the inside of the PID.

__________________
pentiumone133 is offline
 
Reply With Quote Quick reply to this message
Old 02-05-2013, 02:03 PM   #10
machfive55
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jul 2009
Location: Lancaster, PA
Posts: 122
Liked 9 Times on 9 Posts

Default

Quote:
Originally Posted by pentiumone133 View Post
I was thinking about this more, and if the issue is different types of metals creating a reaction and throwing off the temperature then how is it possible to connect the thermocouple to the PID at all? The wires crimp onto lug connectors. These lugs, I assume, are standard lugs not made out of specific material. Then, the lugs are screwed onto metal screws on the PID, which, again I assume are not made out of specifica materials. THEN....inside the PID there is traces and connections on the boards before it actually gets to its final destination in the logic, right?

How does this work? Its the same concept as cutting the cable in the middle and soldering in a copper wire. The metal type changes two or three times already between the sensor itself and the inside of the PID.
I had this thought too. What I am understanding from previous posts is that as long as all these junctions occur at the same temp then it works, its when you have a temp delta across the junctions that will cause inaccuracies?
__________________
machfive55 is offline
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Where to Buy Thermocouple or RTD? RonRock DIY Projects 25 01-31-2013 02:10 AM
Tet-612 thermocouple help! ftlstrings Electric Brewing 11 01-20-2013 08:31 PM
tank plug gas vs tank plug liquid JLivermore Beginners Beer Brewing Forum 6 12-09-2012 12:26 AM
Which thermocouple to use? kburden1 Electric Brewing 6 10-26-2012 06:42 PM
Thermocouple or thermocouple wire source? e lo Equipment/Sanitation 22 11-08-2007 08:09 PM