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

摘要

The mass dissemination needs to be conducted in various air density conditions and even vacuum condition after redefinition of kilogram. This paper discussed the influence of temperature, humidity and air pressure to the air density using the CIPM 2007 forum method to the high precise weighing process. The stability of air pressure to the mass determination process is discussed experimentally using the new M-one mass comparator. When the temperature and humidity are well controlled inside the weighing laboratory, the air pressure should also be controlled to achieve precise mass measurement. 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. Experimental results indicate that weights with hollow structure in the middle can reduce the influence of air pressure to the weighing process.