Variances, Covariances and Restraints in Mass Metrology

The use of Linear, Ordinary Least-Squares Estimation in mass metrology leads to singular normal equations. In the classic approach the singularity is avoided by using the method of the Lagrange Multipliers. A Gauss-Markov approach is suggested instead and its effects on the estimates and on their covariance matrix are discussed. A practical application is presented.