Dear authors

I finally received a second review on the revised version of the manuscript. I ask you to follow the recommendations of the two reviews before it will be accepted for publication. Thank you.

Reviewer 1: Table 5 column headers are still difficult to read due to automatic line change. Please reformat for better reading.

Reviewer 2: Thanks a lot for your very thorough inspection. I think it is important to study on temperature drift on mass. I would like to kindly request to answer (or describe) below additional points before publication.
1. Please add more information (or reference) on the AIST reference in Page 5.
2. Please show us the measured weighing values(in mg) of the components in Table 2.
3. Please add uncertainties’ sources (how to calculate) of each uncertainty factors as well as each component in Table 3. And please add a summary table (total uncertainty budget of a sample cylinder) with all uncertainty factors.
4. Please write (add) their uncertainties of the final purities in Table 4.
5. For decision of CO2 amounts, please describe how to calibrate the CRDS.