Patent ID: 7773231

Claim:
A differential pressure measuring system comprising: a light source configured to emit an emitted light; a first transducer configured to attenuate an intensity of the emitted light in a first wavelength range, depending on a first external pressure to be applied, and to provide a first measurement light; a second transducer configured to attenuate an intensity of the first measurement light in a second wavelength range, depending on a second external pressure to be applied, and to provide a second measurement light, the second wavelength range being different from the first wavelength range; a feedback circuit configured to adjust the intensity of the emitted light to maintain an intensity of the second measurement light in one of the first and second wavelength ranges constant; and an intensity-based measuring module configured to measure a differential pressure between the first external pressure and the second external pressure, based on the intensities of the second measurement light in the first and second wavelength ranges.