The scooper will accurately measure the powder that was sold with the scooper. If use the scooper for another powder, like dextrose, the weight could be different from the weight of the serving size of the protein powder for one scoop of that protein powder that is listed on the protein powder label.
For example, 1/3 a cup of dextrose is 75 grams of dextrose, but 1/3 a cup of protein powder may only be 40 grams of protein powder. The same thing can happen with smaller amounts, in this case, scoops.