ISO 29581-1:2009 specifies the methods for the analysis of cement by wet chemistry.ISO 29581-1:2009 gives the reference methods and, in certain cases, an alternative method that can be considered to be equivalent. In the case of a dispute, only the reference methods are used.It is permitted to use other methods provided they are calibrated, either against the reference methods or against internationally accepted reference materials, in order to demonstrate their equivalence. In case of dispute, only the reference methods are used.ISO 29581-1:2009 describes methods that apply principally to cements, but which can also be applied to their constituent materials. They can also be applied to other materials, the standards for which call up these methods.Standard specifications state which methods are used.