Hi Edwin,
First of all, thank you for putting time and energy in the SMT172 library. I am sure that it is going to be very useful for a lot of people and I am sure that your library will also be another piece of the IOT puzzle.
You have correctly stated the values for accuracy and resolution as you see them on their webpage, but I was informed that this is going to be changed a bit.
Information for other readers:
Fully understanding these specs takes some very good reading. I would just like to point out the following. When you apply the linear equation that translates the dutycycle value to a temperature, then you get an absolute accuracy of 0.25°C. This is related to the fact that the SMT172 had to be compatible to its predecessor the SMT160, so old software could still be used. The SMT172 allows for a better accuracy, if you use the quadratic formula (you find all this in the datasheet). If you do this, the absolute accuracy is better than 0.1°C. Since the noise is better than 0.001°C you can get a resolution close to this value. (The Smartec SMTAS usb temperature boards show the temperatures with a resolution of 0.01°C.)
Another difference between the SMT160 and the SMT172 is that the SMT172 uses so called dynamic element matching (DEM), which is the reason why measurements have to be taken over a multiple of 8 periodes, in order to achive the stated accurary.
You can find the full specs in:
http://www.smartec-sensors.com/assets/files/pdf/sensors/SMT172-Datasheet-V12.0.pdf.
Bob