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.
http://www.capgo.com/Resources/Temperature/Thermocouple/Thermocouple.html
Perhaps my knowledge of thermocouples is outdated, I know only the bare metal ones.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 : Melexis Contact-less Infrared Sensor - MLX90614 5V [MLX90614ESF-AAA] : ID 1748 : $15.95 : Adafruit Industries, Unique & fun DIY electronics and kits
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.
Russell.
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:
http://www.ebay.com/itm/1-6mm-24-Ceramic-Fiber-Heat-Insulation-Blanket-Wood-Stoves-Inserts-/271673466700?pt=LH_DefaultDomain_0&var=&hash=item3f41001f4c,
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
Thermally Conductive Epoxy Adhesives | MasterBond.com ?
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.