Thermocouple doubt

Hi Folks, I just bought a MAX6675 Thermocouple module on ebay and i'm wondering if it's good for what i need. I need to mensure the surface of an electrical resistence, But... there's no risk of a short circuit? I can touch the sensor on the surface?

Thanks in advance.

A thermocouple is bare metal. If the resistor has also bare metal at the surface, you have a shortcut !

It seems that some thermocouples are encapsulated. Perhaps my knowledge of thermocouples is outdated, I know only the bare metal ones.

You can try a contact-less IR temperature meter. They are a few dollars on Ebay and those are already very handy. Fluke has good quality meters of those.

A contact-less sensor for the Arduino could be this :

You can get mineral insulated thermocouples. Unfortunately they are housed in a metal sleeve so, while the sensor is insulated from the sleeve the sleeve could still give a short circuit on something like a surface mount resistor.

I have seen thermocouples encapsulated in glass beads but they will be expensive. How about taking a bare thermocouple and encapsulating it yourself in a tiny drop of epoxy resin?

IR sensors have a wide field of view so may not be suitable.


Use a TO220 insulating sheet (rubbery grey heat resistant electrically insulating and
thermally conductive material)? Check the temperature range though.

Thanks for the tips!!
I researched those options… A contact-less sensor would be perfect, but I might not work on temperature lower than 350º (not sure).

TO220 only hold 220ºC, but i used the idea to find this material:,

What do you think? it’s an insulating material, but it can hold the heat instead… epoxy resin would handle high temperature?

or something like that ?

I found the mineral insulated,

Thanks a lot guys!

Resistive wire at 350 degrees, I call that a toaster. A thermocouple is not accurate to measure a room temperature, but it is the best option for high temperatures. Those mineral encapsulated ones still allow high temperatures. I think you made the right choice.