Problem with K Type Thermocouple

[dcorbett]

I have recently been running into problems using the K-type thermocouple and Max 31855 breakout board. I am using the thermocoupes to measure the temperature inside an agarose gel, you can imagine it like stiff jello. This is an aqueous environment.

The first two days I used my setup I did not run into any problems, but now when I submerge 4 thermocouples into the gel, I am not getting a reading. The thermocouples record temperature just fine in air or water so I don't believe this is a wiring issue. I have also noticed that if I submerge 1 thermocouple in the gel and leave the remaining three in air I receive temperature measurements from all 4 thermocouples.

I'm quite confused as to why this is happening, could they have corroded in this short a time? Any help would be much appreciated.

[Franklin97355]

It sounds like your gel is conductive and the signals are getting shorted out. You may need to insulate the junction and cable inside the gel.

[adafruit_support_bill]

Insulated probes can be found at most industrial suppliers. Omega Engineering probably has the widest selection. Any K-type probe will work with the Max 31855.