A novel automatic mass comparator with a resolution of 10 ng for calibration of masses below 2 mg.

This paper presents a novel mass comparator designed for the purpose of measuring small weights of 2 mg and lower, with readability of 10 ng. The mass comparator was developed using new types of coil and actuator. The added protective ring decreased the average sorption-induced mass variation for the coil by 84%. The accuracy of the novel comparator was verified in terms of stability, Type An uncertainty, and repeatability. Compared to the device of the best available accuracy, the standard uncertainties of the novel-design comparator were approximately 70% narrower. • New design of mass comparator with readability 10 ng was presented. • The effect of ambient conditions, such as mass variation, was minimized. • Stability of the measurement results was 65 ng. • Repeatability was 100 ng. • Proposed design of coil and actuator proved to be advantageous. [ABSTRACT FROM AUTHOR]