Evaluating the salt content of salt-contaminated samples on the basis of their hygroscopic behavior. Part I: Fundamentals, scope and accuracy of the method

The hygroscopic moisture content (HMC) method for determining the salt content of salt-contaminated samples is described and discussed on a theoretical basis. It is shown that the method may allow either an absolute or a relative (quantitative or qualitative) measurement of the salt content, in the case of samples contaminated with salts of known or unknown thermodynamic properties. Possible criteria for detecting the appropriate end-moment of the test are discussed. It is demonstrated that the accuracy of the HMC method strongly depends on the capability of the climatic chamber for maintaining homogeneous and stable environmental conditions. Acceptability of the error associated to HMC measurements depends on the specific purposes of the test and, thus, requires a case-by-case evaluation.