exhaust tube temperature probe and artisan graphing

[Chert]

My TC4 setu gives me four temperature probes.

I've gat BT, ET, MET and for awhile I measure ambient but that is quite stable where I roast.  So lately I've been reading a temperature near my  heat source as a measure of the application of heat.

I think I wish to explore the temperature at the exhaust tube.

I can drill a small hole near the faceplate on the J tube and put a bare TC there, but I think it may get damage from the beans that move up in there.  And I also am uncertain how I would seal around that little glass insulation coated wire. 

More complicated would be to remove the faceplate and drill a hole to place tap there for a thread TC.

Have any of you seen a mod like that?  How would you  go about that modification?

I think our dear founder and head moderator is already asking herself, "Why the heck do that?"  And so I pose the question: Why should I?  The biggest why not is that once the hole is there, there it will stay. 

Will I derive some useful or at least interesting information about heat transfer?

Might it help me decide if the new insulation I am planning to install makes a difference?  Or could I use it to compare my current insulation with insulation removed?

[SusanJoM]

Yup.....you read my mind 

Where on this diagram are you thinking to drill?

https://www.hukyforum.com/index.php?action=gallery;sa=view;pic=38

As to re-plugging a hole?  I'm sure Hans Brinker could send you a small boy to do the job

[Chert]

I'm not sure what diagram.  about 9 o'clock - 10 o'clock position of the exhaust tube 1 cm in front of faceplate, 2 cm above tryer hole.

[Chert]

Here's the first graph with the exhaust probe.  This one is just a bare TC.  It occurs to me that it may be against the metal and reading the roaster temp rather than the air. 

I intend to place a tube across to slide the probe into, and I think I need some way to isolate that stainless probe sheath from the metal of the roaster in order to measure what I am after, exhaust air, not exhaust tube metal.

I also included the warm up phase, first of two roasts tonight.

[Chert]

I'm think the probe should measure closer to the faceplate, maybe that information would be more useful since the ambient temperature of the exhause pipe may average out as it quickly cools the air.

Still pondering...

[SusanJoM]

Could you put it into the exhaust tube itself?  Right at it's inception?
Like this?

[beananimal]

On my Huky (perforated drum, J-pipe) about 2 years ago I drilled a hole in the bottom-flange of the J-pipe and put in a plain cable probe hanging down in the exhaust elbow.
To my interpretation it is by far the most consistent environment probe, as the MET above the perforated drum gives me results I don't understand. (for me it is a miracle to get the same temperature on pre-heating for BT and ET, while I saw with the T-model and solid drum it is very easy).

The handling was a little bit uncomfortable and when removing the J-pipe for filling-in the beans, it gives a drop on the graphs.

In my current experiment model I already drilled a 5mm hole right above the elbow (T-model) and put in a probe with M6 thread and only 10mm length. If I really don't like the position, I can put in a little srew.
Sorry for not having pictures yet, but this shall change within the next 2 weeks.