Abstrato

The Role of the Sensitivity Coefficient on the Authenticity of the Unc

R.Hegazy, M.I.Mohamad

Sensitivity coefficients are essentially conversion factors that allow one to convert the units of an input quantity into the units of the measurand. Sensitivity coefficients are also, and more importantly, measures of how much change is produced in the measurand by changes in an input quantity. Mathematically, Sensitivity coefficients are obtained from partial derivatives of the model function with respect to the input quantities [1]. Many laboratories use the value of the sensitivity coefficient equals one for every input quantity without performing the partial derivatives. They use the value one just to express the uncertainty of the input quantity as a percentage which is not true. The aim of this work is to demonstrate the difference in the uncertainty values calculated by using the sensitivity coefficient by the partial differential equations and by using percentage values through examples in hardness and tension tests. The examples show high difference between the two methods.