1. A device for validating measurements of a dynamic magnitude x coming from an article having placed thereon three main sensors for sensing, respectively, along three concurrent main axes forming a basis e={e 1 e 2. .. e p } of a physical space having p=3 dimensions, the three main sensors serving to measure components V j of said dynamic magnitude x along, respectively, the p=3 main axes, and the device comprising: at least two additional sensors for measuring at least two additional components of said dynamic magnitude, said at least two additional sensors being placed on said article for sensing along at least two additional axes that are concurrent with said three main axes and that are not contained in any of the planes defined by any pair of said three main axes, said main and additional axes forming a set a={a 1 , a 2 ,. .. , a q } of q observation axes, where q>p, and said three main and additional sensors together form a group of observation sensors; determination means for determining an estimator U representative of said dynamic magnitude from said components V j j ε1:q delivered by said observation sensors along, respectively, the q axes; validation means for validating said determination of the estimator U representative of the dynamic magnitude; error detector means for detecting a measurement error associated with said determination of the estimator U representative of the dynamic magnitude; localization means for locating valid components of said dynamic magnitude not giving rise to said measurement error; and reconstitution means for reconstituting a new estimator U representative of said dynamic magnitude from said valid components delivered by said observation sensors, wherein the determination means for determining the estimator U representative of the dynamic magnitude comprise: first calculation means for calculating an observation matrix M that synthesizes the geometrical configuration of said observation axes, the observation matrix M of dimension p×q being defined by M=C.A, C being the matrix of the direction cosines of the basis e, and A being the matrix component of the set a of q axes; first calculation means for calculating an estimation matrix L from said observation matrix M satisfying L. T M=I p ; and first calculation means for calculating said estimator U representative of the dynamic magnitude as a function of said estimation matrix L of said components V j measured by said observation sensors.