Most of the literature that I have read on non-relativistic wave mechanics discusses experiments that measure a particle’s position (double-slit, etc.). But I have found almost no examples of experiments for measuring a particle’s momentum. In general, I know that one measures the momentum of a charged particle by measuring its angle of deflection while passing through a magnetic field. But how does one determine such an angle without knowing the particle’s position at the same time? Please clarify. Thanks in advance.