I have a thermocouple with one end connected to +24V. I want to be able to read the voltage (-5mV - +20mV) on it using a 3.3V ADC. The most reasonable solution I see is lowering the voltages using resistor dividers, than two voltage followers and a differential amplifier (like here: https://electronics.stackexchange.com/a/93467/61946).
I could also power the op-amp from a higher voltage rail, though that would mean constraining the output voltage in some other way.
Is there a simpler solution I am missing?