TIMS measurements of full range of natural Ca isotopes with internally consistent fractionation correction

- Unique simultaneous measurements of the full range of Ca isotopes were performed.
- The Ca isotopic compositions of the standards SRM915a and SRM915b were measured.
- Previously published Ca isotopic compositions were checked for internal consistency.
- A first-order exponential law does not fully correct instrumental mass fractionation.
- The proposed modifications better correct instrumental mass fractionation.