Verifying the Reliability of a Voltage Balance Apparatus to Measure Small Mass and Force Standards at NMIJ

For the accurate measurement of small masses and forces, a voltage balance that uses electrostatic force between electrodes has been developed at the National Metrology Institute of Japan (NMIJ). This voltage balance enables traceable mass and force measurements based on the revised definition of the kilogram, as per electric standards. To confirm the reliability of the developed balance apparatus, the mass of a 2 mg wire weight was determined. The first complete uncertainty analyses were performed, following which the relative standard uncertainty of the mass measurement was estimated to be 5.3 x 10(-4) . The mass of the weight was measured via the submultiple method in a traceable manner with respect to the mass standard at NMIJ. The results obtained from the two different methods were observed to be in agreement within their uncertainties.