we have build a Design with ADS124S08 ADC for measuring 6 Themocouples.
Everything is working as expected when the Thermocouple shield is not connected.
The Shield is connected to the junction.
If we connect the Shield to GND the Measured Voltage (Diff) is wrong.
TC+ = +4mV
TC- = -4mV
Diff should be 8mV but the ADC reads around 0,5mV
Without shied the ADC reads 8mV
So what is wrong in our Design?
Should we use a Bipolar Supply?