ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables. TDR waveform relative length Time domain reflextometry, apparent length divided by probe length. Square root of dielectric Originally from the CUAHSI HIS VariableNameCV. See: http://his.cuahsi.org/mastercvreg/edit_cv11.aspx?tbl=VariableNameCV.