A method and system for the external calibration and recalibration of a blood pressure monitor comprising a continuous pulse waveform detector, a pulse decomposition analyzer for analyzing high resolution pulse wave forms, and an absolute blood pressure monitor. Upon startup, the pulse waveform detector is initialized by the pulse decomposition analyzer based upon a reading from the absolute blood pressure monitor. Upon detection of a physiological event from the pulse decomposition analyzer, the absolute blood pressure monitor is directed to take a reading which is then used to recalibrate the pulse waveform detector.