On the Salecker-Wigner-Peres Clock and Quantum Tunneling

We consider the Salecker-Wigner-Peres clock formalism and show that in the approach introduced by Peres it can be directly applied to quantum tunneling. Then we apply this formalism to the determination of the tunneling time of a non relativistic particle through a double barrier potential. In special, we consider the case in which the clock runs only when the particle can be found inside the region \emph{between} the barriers and analyze the limit of opaque barriers in order to discuss the generalized Hartmann effect.