Bilateral comparison of high vacuum primary standards between the Korea Research Institutes of Standards and Science (KRISS) and the National Measurement Institute of Japan (NMIJ)

The bilateral comparison of high vacuum primary standards between the Korea Research Institute of Standards and Science (KRISS) and the National Measurement Institute of Japan (NMIJ) was performed in the nominal pressure range 4.09 × 10−3 Pa to 1.22 × 10−2 Pa by using two spinning rotor gauges as transfer standards. The accommodation coefficients (σ) of the two rotors for N2 determined by the two laboratories agreed to within 0.17% for rotor 10 and 0.89% for rotor 11. This agreement is within the expanded uncertainties (k = 1) of the primary standards at the two laboratories.