Fiber Optic Bragg Grating V-Cone Flow Sensor

In this paper, theories and experimental accomplishment of the fiber optic grating based V-cone flowmeter are presented.As a differential pressure (DP) type flowmeter, the basic theory of the V-cone is Bernoulli's equation, which is similar to traditional DP flow sensors. However, the distinctive geometric design of V-cone presents many advantages over the traditional ones: flexibility for harsh installation, low energy consumption.In addition to all the advantages of fiber sensing technologies, fiber optic grating sensors possess the distinguishing characteristics for its wavelength-modulated feature, such as immunity to the fluctuation of the light source or the light loss during transmission, capability to realize WDM (Wavelength-Division Multiplex) sensing network or distributed measuring system etc. Therefore, the study was carried out to develop a perspective fiber optic grating flow sensor.For this, the sensing part, based on V-cone (a type of differential pressure flow sensor), utilized FBGs (Fiber Bragg Grating) as the sensing probe elements; the demodulation part made use of another kind of fiber optic grating, LPG, in the light of its approximate linear edge; the processing circuit chooses the TMS320LF2407 DSPs to achieve real-time data analysis. All fiber sensing system was completed using FBGs and LPGs.