According to datasheet: The ADC produces a digital output that is equal to the ratio of the RTD resistance to the reference resistance. A reference resistor equal to four times the RTD’s 0 degC resistance is optimum for a platinum RTD. Therefore, a PT100 uses a 400 Ohm reference resistor, and a PT1000 uses a 4kOhm reference resistor.

I have attached Table 9 from the datasheet in which the temperature in degC, the resistance of RTD, and the ADC code (dec) are given for PT100 with Rref = 400 Ohm.

The ADC code (dec) is 8192 at 0 degC

The ADC code (dec) is 11346 at 100 degC

Does it means that there are almost (11346 - 8192)/100 = 31 steps or measurement points for each degC ?

 

One more question. The last colum of Table 9 is the temperature we get from this formula ADC CODE/32-256 (°C).
Given the ADC CODE we can get the temperature but there is an error.

The formula calculation of 240.91 actually corresponds to 250 degC ?
The formula calculation of 98.56 actually corresponds to 100 degC ?
The formula calculation of -208.59 actually corresponds to -200 degC ?