Attaching a thermocoupler

[infinitymike]

I want to monitor my supply and return temps so I bought these digital read out thermometers.
Should I attach them to black pipe or copper?
Do I just tape it to the pipe with electrical tape and then insulate over it?
Do I put some sort of conductive material on it, say like dielectric grease?

 

[Tennman]

MIke for my AZEL thermistors, which look just like your thermocouple, I tie wrapped them to the black iron and insulated well around them to try to make the far side of the thermistor as close in temp as the edge touching the pipe. I didn't pot them in anything and they seem to work fine. I'd strip off the shrink wrap covering at the base so the whole edge of the thermocouple rests on the pipe. Some type of conductive potting would no doubt be better to get the whole shell to the same temp, but conduction and insulation seem to make that happen pretty well.

 

[maple1]

I've just got mine tie-wrapped under some pieces of pipe insulation. Doesn't matter the type of pipe. I didn't strip anything. They seem to react pretty quick & work pretty good.

 

[ewdudley]

It shouldn't make enough difference to matter for what you're doing, but If it's convenient you can try to get an extra foot or two of wire under the insulation as well, by running the wire along the pipe for a ways, or by folding the wire (gently) back and forth six inches at a time under the insulation. Depending on the wire and the sensor, the wire can conduct significant heat in some situations.

 

[Tennman]

I should clarify my stripping comment, I'd only strip the 5/8"-3/4" where the shrink wrap steps up onto the thermocouple sheath so the whole sheath is metal to metal contact with the pipe.

 

[infinitymike]

It shouldn't make enough difference to matter for what you're doing, but If it's convenient you can try to get an extra foot or two of wire under the insulation as well, by running the wire along the pipe for a ways, or by folding the wire (gently) back and forth six inches at a time under the insulation. Depending on the wire and the sensor, the wire can conduct significant heat in some situations.

Thats interesting, I thought that the sheathing/shrink wrap would get damaged if it stayed in contact with the heat source ultimately damaging the wires. I figured that the metal end protected the wiring. Once again Hearth is an amazing source of information.

 

[infinitymike]

I should clarify my stripping comment, I'd only strip the 5/8"-3/4" where the shrink wrap steps up onto the thermocouple sheath so the whole sheath is metal to metal contact with the pipe.

Gotcha

 

[infinitymike]

I'm also hooking this up to read my gasification temps. And when I was dry fitting the wire it touched a live wire and arced. Here is the damage.
I tested it in the tip of my MAPP gas torch and it got up to 1200*
It is a bit stiff/brittle right there.
It's hard to see if I actually burnt through the metal braiding. I don't have a magnifying glass either.
Do you think I did any read out damage ?

 

[Tennman]

put it in boiling water and see if it measures 212F or 100C. Probably fine.... but you can shorten at the damaged spot with no affect to measurement accuracy as long as both leads are equal length.

 

[infinitymike]

put it in boiling water and see if it measures 212F or 100C. Probably fine.... but you can shorten at the damaged spot with no affect to measurement accuracy as long as both leads are equal length.

The lowest it will read is 300*f
But it seems to be fine.

 

[avc8130]

The lowest it will read is 300*f
But it seems to be fine.


View attachment 124699

Is that up and running REAL numbers?

How about a pic of the gassification monitor?

ac

 

[infinitymike]

Is that up and running REAL numbers?

How about a pic of the gassification monitor?

ac

Not sure what you mean. But here's the gasification connection

 

[infinitymike]

That was real time.
Here's another real time one.

 

[maple1]

Cool.

Got a link to your thermocouple & guage for it? The other ones look the same as my Hong Kong Ebay Specials, but I don't think they were selling the high temp stuff, at that time at least.

 

[infinitymike]

Cool.

Got a link to your thermocouple & guage for it? The other ones look the same as my Hong Kong Ebay Specials, but I don't think they were selling the high temp stuff, at that time at least.

I got the 3 LED lights to indicate zone operation on ebay at
http://www.ebay.com/itm/22MM-LED-Pi...ED-/300998370700?ssPageName=ADME:L:OC:US:3160


I got the supply/return gauges on ebay at
http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=271103991203

I got the gasification gauge at
http://www.GlowShiftDirect.com/red-digital-led-exhaust-gas-temperature-gauge.aspx


I got the control box from my electrcian for free.
Its a CCTV box and has a 110v to 12v transformer inside with 8 circuits.
The 3 guages are 12v and just plug into 3 of the 8 circuits.
The 3 LED's are 110v and I ran 14/3 romex from the ARGO zone box over to this box.
Each light uses 1 leg of the 14/3 and all 3 lights use the same ground.

 

[ALL4GLH]

So, I'll resurrect and old thread rather than start a new one. What did you use for a power supply? I got my WG setup too late in the year for me to mess with too many things.

I still need a thermic valve for return water temps (although it's at ~150-160 when not on load).

I was looking at something like this:
http://www.amazon.com/Distributed-P...=1-8&keywords=12v+dc+distributed+power+supply

Although I'm not sure of the amperage of the gauges that are used.

 

[infinitymike]

That's pretty much what I used.
My electrician gave me a CCTV box he ripped out of a job. It plugs into a wall outlet and converts the 110vac to 12vdc
The gagues are 12v and pull 30mA.

The zone lights I have are 110vac and I have them connected with regular romex wire right off the circ pump in the Argo zone control box.

 

[infinitymike]

I did burn out that K type thermocouple for the gasification temperature.
It burned out in 2 months, the tip melted off.
I bought another one from Glow Shift and it lasted about 10-11 months, not sure exactly, it's very thin and not worth the money.
I bought another coupler from eBay that I just hooked up, it's 3/8" thick. I hope this lasts a lot longer.
http://www.ebay.com/itm/High-Temp-T...888?pt=LH_DefaultDomain_2&hash=item3a9f031688

I guess you could use this gauge for a display.
http://www.ebay.com/itm/Digital-DC-...Parts_Accessories&hash=item58bbc12a49&vxp=mtr

Wow, I realize how much I OVER PAID for the Glow Shift one and the direct replacement probe.
I could buy 10 of these setups for what I paid

 

[infinitymike]

ALL4GLH, did you have any pics of your set up?
we ALL love to see pics.

 

[ALL4GLH]

Not yet, been busy trying to make sure it's all set up. I'll get some this week sometime.

Good to know I'm on the right track. I'm going to see what others are using for the pyrometer, I had one in my CB that was pretty accurate. Would hate to keep replacing them.