Experimental research on the high accuracy mass determination between stainless and silicon sphere mass standards

Abstract

After the redefinition of kilogram, the mass determination process may carry out in many conditions, such as vacuum, normal air condition or inert gases. To achieve high accuracy and stability mass determination process, not only the influences of environmental factors such as temperature, humidity, air pressure and contents of CO₂ need to be carefully evaluated, the shape of weights can affect the stability of weighing process. The standard deviation of weighing process is a very important parameter to evaluate the stability and reliability of weighing process. This paper continually compare and analysis the weighing process between cylindrical stainless weight and silicon sphere with nominal value of 1kg under the same air condition. And the experimental results demonstrate that the air flow near the weighing area can affect the weighing process. When all the other air conditions such as temperature, humidity and pressure, are well controlled and keep stable, comparing with others shapes of weights, the ball shape weights have the biggest deviation of weighing process.