How can the temperature affect the performance of a classical pipeline model when plastic pipes are used?

In this paper, it is shown that the time-invariant nonlinear model normally used to design algorithms to isolate leaks in pipes can introduce errors when the pipe in question is a plastic one exposed to temperature changes. Thus, this model must have a mechanism to compensate temperature variations, if it is desired that such model follows in a more accurate way the dynamics of a liquid. A comparison of the behavior of the model with and without temperature compensation is made using real data coming from a plastic pipeline prototype transporting water.