Reliability Check of a Voltage Balance to Measure the Radiation Pressure for Small Mass and Force Standard at NMIJ

The precision measurement of radiation pressure force, especially in a manner traceable to the International System of Units (SI) is of importance. For the precision measurement of radiation pressure of optical laser, a voltage balance which uses electrostatic force between electrodes has been developed at the National Metrology Institute of Japan (NMIJ). The voltage balance enables mass and force measurements traceable to the new definition of the kilogram. To confirm the reliability of the balance, the mass of a 2 mg wire weight was determined. The relative standard uncertainty of the mass measurement was estimated to be $8.4\times 10^{-4}$. The mass of the weight was also measured by a commercially available electronic balance. The masses determined by the two different methods were in agreement within their uncertainties. Details on the measurement system and result are presented.