The international metrology community renamed their moving-coil watt balances as 'Kibble balances' in honour of the pioneering work in this field by Dr Bryan Kibble, who passed away in 2016.
The main distinctive feature of the BIPM Kibble balance is its implementation of a one-mode measurement scheme, in addition to the conventional two-mode approach. In the one-mode scheme, a current flows through one of the windings of a bifilar coil in both weighing and moving measurements. The scheme hence makes the experiment less sensitive to changes in the magnetic field which varies with the coil current and alignment as compared to a one-mode Kibble balance. In addition, a comparison of measurements carried out using the two schemes may provide a better understanding of the limiting factors and possibly reveal some unexpected effects unique to each technique.
|The BIPM Kibble balance|