The thermocouple needs diferential voltage to read the temperature.
I'm using mux74HC4067 to read 16 thermocouples linked in single end. I mean, I hookup all negative legs of (16) themocouples in the negative pin of ad595 and "signal" linked in positive pin of AD595. The problem is noise in the signal reads.
The question is:
How can I use two mux74HC4067 to multiplexing 16 thermocouples?
One mux with positive signal and other mux with negative signal. Each signal to the respective negative and positive pins of AD595.