Progress on the BIPM watt balance

This paper reports the latest advances made on the BIPM watt balance experiment. The improved apparatus is now fully assembled. The new, open support structure allows convenient access to all key components of the apparatus. This, together with the alignment mechanism will allow to improve significantly the alignment accuracy. The magnetic circuit was aligned to better than 10 μrad with an uncertainty of 20 μrad. A new interferometer based on space-heterodyning techniques has been integrated.