To provide a differential pressure measuring system capable of forming an interference fringe on a light receiving element by correcting an optical path difference.
This system is equipped with a light source 4 for irradiating light, the first measuring sensor 5 for imparting the first measuring optical path difference to light according to the first external force PO1, the second measuring sensor 15 for imparting the second measuring optical path difference to light according to the second external force PO2, an interferometer 28 for imparting an interferometer optical path difference to light and forming the interference fringe, an optical path difference compensation means 128 for branching light and imparting a compensation optical path difference which is larger than a value determined by subtracting the maximum value of the interferometer optical path difference from the optical path difference between the sensors to either of the branched light, and a signal processing device 7 for calculating the difference between the first and second external forces PO1, PO2 from the interference fringe.
Iwa Saki Kokuni
Akira Kurihara
Kawamata Sumio
Masakazu Ito
Shunichi Takahashi
Toshio Takamatsu