Parameter of the signal – A useful construct of a measurand

•A parameter of the signal segment is proposed as an extended model of a measurand.•Reducibility conditions to a classical model are given.•For non-point parameters a sub-set of averaged parameters is separated.•Attributes of the averaged parameters are specified and discussed.

The purpose of this paper is the formulation of a consistent template for a measurand description. A parameter of the selected part of the signal is proposed here as a general and useful model of the measurand. Next, the physical and technical reasons are given for such a model. Then, conditions are formulated to describe when it is possible to simplify the proposed extended model of the measurand to the model constituted by a value of a single individual quantity. The conditions are that the measured parameter must be quasi-point (i.e., quasi-local, quasi-instantaneous, etc.) and reflexive. The definitions of both of these notions are provided and discussed. In particular, in a set of non-point parameters, a sub-set of averaging parameters is defined as those being reflexive, symmetric, bisymmetric, cancellable and continuous.