High Temperature Sensor

Question

I would like to use a Raspberry Pi to build an electric controller for my electric smoker based on monitoring precise temperature. The current electric controller built into the electric connector is too coarse in controlling temperature. Where can I obtain a high temperature sensor or sensors that I can mount within the smoker cabinet. The smoker cabinet can run as hot as 400 degrees Fahrenheit, but I typically run it at 225 degrees Fahrenheit. Thank you for your attention to my question.

gdstew · Answer

The only temperature sensors that I am aware of that works at those temperatures are thermocouples. I did a quick google of raspberry pi thermocouple interfaces and got a few hits so you should probably start there to find something at a price you are interested in. None of the ones I saw had the thermocouple sensors included though I would be surprised if you could not find one that did. Also be aware that there a a few different types of thermocouples and that the interface you buy must be designed to work with that type of thermocouple.

michaelkellett · Answer

The cheapest thermocouple I could find that will take 350C is 7069224 from Farnell for about £5. It would probably need protection but should be OK in an iron tube.

You'll need the interface as well of course.

MK

jc2048 · Answer

My first thought was thermocouple, too, but a pt100 sensor can also go to over 400C if it's a wound element, in appropriate casing, with suitable lead insulation. Here's an example https://uk.farnell.com/labfacility/xf-960-far/resistance-thermometer-pt100-100mm/dp/2749489?st=thermometers One of the technical documents linked to on that page covers the pros and cons of pt100 versus thermocouples [it's probably reasonably fair and neutral because Labfacility make both]. Whether it would work for you mechanically, having a probe entering from outside like that, I don't know. You'd still need conditioning for the sensor. 2749489 2749489