Dynamic calibration of the fiber-optic pressure based on side-hole fiber

This paper presents a dynamic pressure calibration of the fiber-optic interferometric sensor based on highly birefringent fibers. Earlier we tested other types of fiber optic sensors based on the same principle for measurements of static and quasi-static pressure. In order to be able to apply the sensor for measurements of fast pressure changes, the dynamic analysis is crucial due to occurrence of resonance phenomena and due to possibility of false pressure readings. We applied a static calibration procedure to initially determine the pressure sensitivity and temperature stability of the sensor. Next we compared the characteristics of the fiber-optic sensor to the responses of a calibrated piezoelectric dynamic pressure sensor at an operating range of 110 bar with a sampling rate equal to 200 kHz. The dynamic characteristics of the fiber-optic sensor are in good agreement with those of the reference piezoelectric sensor for the sine pulses of a full width at half of maximum higher than 150 ms. For the sine pulses faster of about one order high oscillations occur in the piezoelectric sensor while only slight oscillations in the fiber-optic sensor. It clearly shows that the highly birefringent fiber-optic sensors can be successfully applied for measurements of rapid pressure changes.