Design And Simulation Of Fiber Grating Microinventory Sensor For Chemical Reagent

The micro stock detection technology is that uses the sensing element to accurately and timely detect the chemical reagent.At present,electrical components is often used for the inspection of chemical reagents.However,the electrical circuits are relatively complex and the electromagnetic interference resistance is weak,so the accuracy of sensors is limited.Due to the anti-electromagnetic interference,corrosion resistance,high optical precision,and simple structure of the fiber grating.In this thesis,based on the novel optical device of fiber grating,method for detecting micro-stocks of chemical reagent is designed.The thesis mainly includes:the theoretical research of fiber grating pressure senor technique,the design about the elastic sensor and simulation of micro-stock fiber grating sensor.1.The theoretical research of fiber grating pressure sensing technique mainly includes:the theory of the fiber grating and the derivation about sensitivity of fiber grating.The periodic structure of the fiber grating makes it reflect a certain wavelength light in the broadband light source and transmit the light of other wavelengths.When fiber grating strains,the wavelength of the reflected light is shifted.By detecting the offset of the center wavelength,the external strain information can be known.Based on fundamental equation,the conclusion about sensitivity in fiber grating is found,it isΔλ=0.783λ?.2.The structural design of senor and model of elastic.The core of the design is that the fiber grating is more sensitive in axial strain than in tangential strain,so that it is necessary to transform pressure to axial strain.Comparing with plenty of sensitive elements,elastic is selected as sensitive element of sensor.The research about the elastic includes:stiffness factor of elastic,size of elastic and installation process of it.By theoretical analysis,besides fiber grating itself,it is found that the offset of the center wavelength is related to basic parameter of elastic.Based on this theory an elastic is used,of which stiffness factor is E=2000kg/mm~2、length is L=20mm、breadth is b=10mm、thickness is H=0.5mm.Then the package is designed according to protection material and device.3.Simulation of fiber grating sensor.Taking the weight of 10g as a baseline,5g-15g was taken as the study range,and 0.5g was taken as interval.The center wavelength was recorded by matlab,and weight-wavelength graph can be drawn.Based on the graph of the measure results,setting known weight,the corresponding center wavelength is recorded by matlab simulation.Then measure value can be known.Compared measure value with the actual value,the error is 0.305%.Through error analysis,it is proved that the design of optical fiber grating chemical reagent micro-storage pressure sensor is feasible.