High accuracy velocity control method for the french moving-coil watt balance

Suat Topsu (1) , Luc Chassagne (1) , Darine Haddad (1) , Yasser Alayli (1) , Patrick Juncar (2)

1 LIRIS - Laboratoire d'Instrumentation, de Relation Individu Système
2 LCM - Laboratoire commun de métrologie LNE-CNAM

We describe a novel method of velocity control dedicated to the French moving-coil watt balance. In this project, a coil has to move in a magnetic field at a velocity of 2 mm s−1 with a relative uncertainty of 10−9 over 60 mm. Our method is based on the use of both a heterodyne Michelson's interferometer, a two-level translation stage, and a homemade high frequency phase-shifting electronic circuit. To quantify the stability of the velocity, the output of the interferometer is sent into a frequency counter and the Doppler frequency shift is recorded. The Allan standard deviation has been used to calculate the stability and a systd of about 2.2310−9 over 400 s has been obtained.

Mots clés: Nanométrologie; contrôle de déplacement et de vitesse; balance du watt

Domaines: Micro et nanotechnologies/Microélectronique

Suat Topsu, Luc Chassagne, Darine Haddad, Yasser Alayli, Patrick Juncar. High accuracy velocity control method for the french moving-coil watt balance. Review of Scientific Instruments, 2004, 75 (11), pp.4824-4827. ⟨10.1063/1.1809302⟩. ⟨hal-00870592⟩