Method and device for measuring a signal representative of a physiological parameter of a user. A body worn device includes a securing band and at least one sensor for measuring the signal. The sensor is arranged on the securing band of the device such that when worn, the at least one sensor abuts against the body of the user. A value of the signal is measured using the sensor. An amplitude envelope control band is defined having an envelope upper amplitude value and an envelope lower amplitude value. The amplitude of the measured value is controlled to be within the amplitude envelope control band by controlling a force pressing the at least one sensor in a direction substantially perpendicular to the body of the user.
