Detection circuits, detection method and systems of measuring physical quantities

摘要

A detection circuit 30 has a unit 30 a for inputting a signal to be detected by synchronized wave detection, a unit 30 b for inputting a standard signal for the signal to be detected and a unit 30 c for inputting an offset signal applied on the signal to be detected. The offset signal is superimposed on the signal to be detected, which is then subjected to synchronized wave detection based on the standard signal.