dhenry:
A few things:
99.9% of the seasoned engineers cannot get a 24-bit adc to work. It requires tremendous amount of know-how and art of engineering (layout in particular).
One approach to get usable data out of a high resolution adc is to average. It has its downside.
In your case, you should get at room temperature close to half of full scale and it varies with temperature.
For what you do, the onboard adc is perfectly fine.
1). I understand that, that is why I ordered the DC570A demoboard, this is designed to use the LTC2440 within spec.
2). the sketch already averages the values it reads from the DC570A
3). I don't understand what u mean with that. Currently when I hold the thermistor between my figures, it start rising to 25C and stops as soon as it hits it.
4). I do need it. I have used a 12-bit ADC controller(which is closed source and I can't change) which gave me 0,03C resolution. I can easily keep my process stable at that. I want to go further.
24-bit my be overkill but I want try and get that. 20-bit would also be good, but the goal is 24-bit.