Thermocouple & Thermowell Fitting

[maxtor]

Okay, with the PID and stuff I purchased, I got a K type thermocouple:

http://www.amazon.com/gp/product/B00ADHNSGI/?tag=skimlinks_replacement-20

Now, I've read that since this thermocouple I got isn't waterproof or stainless steel that something like this may be needed:

http://www.amazon.com/dp/B00VKEKSZW/?tag=skimlinks_replacement-20

Just want to verify that I do need that, because my thermocouple will be submerged in water all the time. Also, is there any type of "contact gel" that's needed in between the two, when my thermocouple gets screwed into the other one?

 

[trimixdiver1]

Looks like that TC threads in. The TC is not exposed, it's in that stainless "thermowell" already. Your good

 

[The10mmKid]

Your T/C is designed to be 'bottomed' out in a 3/8-1/2" deep hole.
Because of the braiding, it is not sealed.

You need a very short thermowell, such as:
http://www.amazon.com/2-1-Thermowell-Stainless-Steel-316/dp/B0091M0WM4/ref=sr_1_2_m?s=home-garden&ie=UTF8&qid=1431826240&sr=1-2&keywords=Thermowell

This one may even be too long.

'da Kid

 

[maxtor]

Your T/C is designed to be 'bottomed' out in a 3/8-1/2" deep hole.
Because of the braiding, it is not sealed.

You need a very short thermowell, such as:
http://www.amazon.com/2-1-Thermowell-Stainless-Steel-316/dp/B0091M0WM4/ref=sr_1_2_m?s=home-garden&ie=UTF8&qid=1431826240&sr=1-2&keywords=Thermowell

This one may even be too long.

'da Kid

It doesn't really give the size of the TC that I have so how would I know if the one you have linked is too long or not? Also, the one in your link, is there more to it then shown? Just wondering how it keeps from leaking as I don't see any seals or even a second nut to seal it tight in the installation hole

 

[The10mmKid]

I wouldn't know the exact size of your threads.
The ones I have installed have been 1/4-28

You may find a watertight T/C for cheaper than the 'well and bulkhead you'd need.
Something like this with an O-ring and a nut:
http://www.amazon.com/Probe-Thermocouple-Sensor-Temperature-Controller/dp/B00899A4LY/ref=pd_rhf_se_p_img_3

These are all just examples, not specific recommendations.

Later,
'da Kid

 

[Bobby_M]

The one you got is mounted within a hollowed out M6 bolt. To insert it into a thermowell, you need to squeeze the crimp with a pair of pliers so that you can slip the bolt off the capsule. At that point you can insert it into any depth thermowell.

 

[trimixdiver1]

The one you got is mounted within a hollowed out M6 bolt. To insert it into a thermowell, you need to squeeze the crimp with a pair of pliers so that you can slip the bolt off the capsule. At that point you can insert it into any depth thermowell.

Oh, I thought they were a solid piece. Now I can see that it's two piece. My bad.


You can always get a weldless thermowell from Brewers hardware.

 

[Bobby_M]

And I sell them too.

 

[trimixdiver1]

And I sell them too.

Sorry, forgot!

 

[augiedoggy]

Unless I missed something, its still cheaper and easier to buy a $4 pt100 which requires no thermocouple... and it will be more accurate in most cases...

I have that exact same TC probe which came with a cheap rex c100 I bought and later swapped but I had discovered myself that the pt100 probes do not need thermoprobes and are a better choice. and never used the tc probe.

 

[trimixdiver1]

Unless I missed something, its still cheaper and easier to buy a $4 pt100 which requires no thermocouple... and it will be more accurate in most cases...

I have that exact same TC probe which came with a cheap rex c100 I bought and later swapped but I had discovered myself that the pt100 probes do not need thermoprobes and are a better choice. and never used the tc probe.

Also stay away from the cheap probes. I've had nothing but issues with some RTD's I got off eBay from China. Got some nice omega RTD for a great price on eBay. For brewing an RTD is cheaper and more accurate.

 

[augiedoggy]

Also stay away from the cheap probes. I've had nothing but issues with some RTD's I got off eBay from China. Got some nice omega RTD for a great price on eBay. For brewing an RTD is cheaper and more accurate.

I've only bought about 9 or the "cheap" rtd-pt100 probes on ebay and amazon but they have all been very accurate? they are the same generic probes many other local seller sell..

I will say they come with the same thin gauge wire in the stainless sleeve just like the tc probe the OP has which is not very good... it catches and kinks easily. I did create a short in the wiring on one by having the cable catch on a doorknob and pull the cable.

I have since switched to using these for easy disconnecting and cleaning... plus the cable is much better and easier to keep clean IMHO.. But I learned the hard way by going the cheapest route and then replacing them later...

http://www.ebay.com/itm/RTD-PT100-T...b&pid=100005&rk=5&rkt=6&sd=251771167963&rt=nc

 

[trimixdiver1]

You have better luck than me. I got the bare elements and none of them calibrated anywhere near the others

 

[augiedoggy]

You have better luck than me. I got the bare elements and none of them calibrated anywhere near the others

That very could be...I have had good luck with the cheap fotek ssrs as well and there have been many reports of failure on those so I believe I got lucky there..
I do have one temp probe thats off by about 3 degrees but the rest are all within a degree or 2 variance before I adjusted my pids to compensate. Its my understanding this is normal.