Processing apparatus, system and method for processing checks in communication with a host computer for accurately detecting check multifeeding. A time difference signal having a pulse width corresponding to the time difference between an output of a resonant pressure sensor and a reference clock is prepared. A handle assembly is attached with a first portion of at least one of the reservoirs and a wheel assembly is attached with a second portion of the at least one of the reservoirs. The locking system prevents the isolation tool from any further movement which would unset it from the desired position. The sample collection unit harvests the collection liquid from the cyclone unit.