I ordered some thermocouples at Procon Ebay as shown below.
They seem to work fine in open air and boiling water.
But however: the moment I put them in my TJ-067 roaster or anywhere else close to iron they are not responding anymore.
My Voltcraft datalogger is working right.
I'm just a layman...........but I hope there's a simple explanation for this matter.

Rgds, Tjibbe



EGT K Type Thermocouple for Exhaust Gas Temperature Probe with M5 Threads

Answering this question requires more data. What precisely does your readout show? What does it do and what does it not do?

As a general stab in the dark, it sounds like your ground wire is not connected on your roaster. Are you using a 2 or 3 prong plug? Are you sure the green wire is connected in your plug? Are you sure the ground is connected inside your wall plug?

50% of initial thermocouple problems are grounding. 49% are configuration problems in the reader. Stuff like not having the type set correctly. 1% is the TC itself. It's "the little foxes, that spoil the vines". If you are getting good reading out of the roaster, check your ground.



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OK they work fine not grounded to roaster correct?
Are you using a laptop?
I found if my laptop is plugged into the AC adapter I always got a lot of noise using Artisan and TC4c

Are you just plugged into your data logger and getting nothing with probes are installed in roaster or nothing using a USB data logger to computer?

I havent plugged the datalogger on to my laptop yet.
I was just putting the TC close to the roasters front-plate and all I see is flat lines on the datalogger, no temperature at all, just nothing.

When you say touch I think you mean touch or ground to metal...
The problem must be electrical noise...

I see you are in Netherlands.. What voltage are you using?

I would remove the steel braiding and wrap wires with Teflon Tape used to seal pipe threads.. If that works find some non-metallic tubing to cover wires.. Maybe you can use the steel over Teflon Tape without tubing.. I would also try direct ground from roaster to house wiring as a test if you have a some kind of voltage transformer between the house wires and roaster...

Also where wires are crimped at M5 bolt the steel braiding maybe too tight and braiding is shorting out a micro amount.. Pull wires out of bolt and wrap with tape and try that.. If it works re-crimp..

All,

Thanks for the help, the thermocouples were grounded, I needed isolated ones which I installed this morning.
ET seems to be pretty accurate, BT about 20 degrees Celsius too low........

Rgs, Rob

In a related question not intended to thoroughly hijack the thread, and I know this question has been put forth before: What is the best thermocouple location for the TJ for both BT and ET?

I'm hearing that directly to left of site glass (on the door) in the picture above is the best, though if you have drum speed control and place the bean mass to you liking, where would you be inclined to locate it? In general I would prefer not to put any probes on the door, though in the end, I'll go with what's best.

Regarding ET, it looks simplest to put the probe in the bean chute/exhaust chimney (again, as pictured above), but is this the best location or simply the easiest to drill through? Mind you I have a drill press and have no problem going through that nuclear reactor-thick faceplate. OTOH, the lower right screw location on the chimney looks like a good spot actually, and I wouldn't even need to drill.

IMHO: Just like above..
Unless you can make a L-shaped probe were you drill the through hole above the door and probe is positioned in the bean mass...

The more probe inside the roaster the closer to the true temp.

If you have a long probe tip in the beans is cooler than part of probe above verses the door threaded mount being cooler because of low door temp. and the tip in the bean mass hotter than bean door and giving a reading a few degrees low..