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Topic: max13855 thermocouple problems (Read 720 times) previous topic - next topic

kanurys

Hi guys,

I am using a MAX13855 thermocouple digital amp to read a k-type thermocouple with my Uno. I have a .1uF cap across the thermocouple leads and the chip communicates well with the Arduino. I'm taking an average of 100 samples and when it settles for a few minutes it seems to be fairly accurate. Accurate untill:...

The problem I'm having is that the temperature reading drifts up or down by around 20 °F when my body gets near the thermocouple or it's leads. I'm guessing capacitance interference of some sort. Is there a way to eliminate this? It makes it very difficult to calibrate, since I have to be near the system to do so.

It also goes kind of wacky when I move the leads around.

Jack Christensen

The datasheet does not recommend any capacitor across the TC leads, what's with that? I have some MAX31855s but have not tried them yet. Had very good luck with its predecessor, MAX6675.

Define "wacky"?
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

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