RESEARCH ON THE INFLUENCE OF AIR DENSITY TO HIGH ACCURACY MASS MEASUREMENT

The mass dissemination needs to be conducted in various air density conditions and even vacuum condition after redefinition of kilogram with the natural constant. This paper discussed the CIPM 2007 forum method and artefacts method to determine the air density. The influences of air pressure to the precise mass measuring process are discussed. The stability of air pressure to the mass determination process is discussed experimentally using the new M-one mass comparator. Due to the change of air pressure, airflow and vibration with regard to the weighing hanger can be arisen. The vibration of weighing hanger is from both the base and the airflow. Under air pressure control, the standard deviation of weighing process can be reduced to 0.39 µg. The air density determination process with artefacts method is under processing.