Hi Chintan,
You haven't told me the capacity of the load cell (total measured weight for the load cell being used) or full-scale deflection (1mV/V, 2mV/V, etc.). Let's do an example. If the capacity of the load cell is 1kg and 2mV/V, when applying 5V of excitation, the maximum output when 1kg is placed on the load cell will be 10mV. The full-scale range of the ADS1232 is +/-0.5Vref/PGA, and for 5V reference becomes +/-2.5V/128, or +/-19.5mV. 10mV is approximately 1/4 of the total range, so the total number of counts possible will be 1/4 of 2^24 (or about 4 million codes).
The total weight resolution (assuming no noise) will be 1000 grams / 4192304codes or about 238 ugrams per code. If we placed a 50 gram weight on the scale we would see a specific change in codes from no weight to measured weight of 50g/238ug or 210000 codes.
Let us now assume the capacity is 125kg. This would change the number of grams per code to 125000/4192304, or about 29.8mg per code. Now placing the 50 gram weight on the load cell would result in about 1677 codes. This ends up being about 10 bits and again assumes no noise. If we have about 7 bits of noise, the results will change dramatically. 2^17 is about 131072. In the 1kg capacity scale the measurable grams per code changes to 7.6mg, and the 125kg scale is 953mg per code. For the last case 50 grams becomes about 50 codes.
So you can see the capacity of the load cell will determine the best case, and the noise will determine the true measureable case.
Best regards,
Bob B