A sensor for physiological measurement is disclosed herein. The sensor includes at least one detector (21) for acquiring a signal indicative of vital sign of a subject. The sensor also includes at least one state indicator (19) for indicating based on the signal acquired by the at least one detector one of at least two different ranges, which ranges are a first range and a second range, the first range being for one of desired vital sign signals and minor alarming vital sign signals, and the second range being for vital sign signals outside the first range. A corresponding method and monitoring system is also provided.
