In this project I will explore the broad potential utility of Ramsey interference measurements for fundamental tests of macroscopic quantum superposition states. First of all, this includes a thorough investigation of the implementation of these measurement protocols with state-of-the-art nanomechanical and trapped ion systems. More importantly, it is the aim of this project to identify new measurement protocols, which also allow entanglement verification between multiple mechanical modes and ultimately the violation of Bell inequalities between two space-like separated mechanical resonators.