Two vector magnitudes, a and b, occurring toghether in a physical phenomenom, can be related by the law b=phi.a where phi is a constant dyadic magnitude (or a tensor of second order). In this case, for certain vector a, there corresponds certain vector b. The law will only be determined after the establishment of phi, which is possible in general by direct measurements of this magnitude. This paper deals with a indirect way to determine phi by some direct (or even indirect) measurements of the corresponding vectors a and b. Incertainties of vectors a and b are considered by a numerical example and the incertainty of phi can be evaluated.
Vector; measurements; incertainties
