A simple, low cost and fast response time intrinsic relative humidity sensor system based on an etched singlemode polymer fiber Bragg (POFBG) is presented in this paper. A macro-bend linear edge filter which converts the humidity induced wavelength shift into an intensity change is used as the interrogation technique. The singlemode POFBG is etched to micro-meters in diameter to improve the response time of the humidity sensor. A response time of 4.5 s is observed for a polymer FBG with a cladding diameter of 25 μm. The overall sensor system sensitivity was 0.23 mV/%RH. The etched POFBG humidity sensor shows anexponential decrease in response time with a decrease in fiber diameter. The developed sensor might have potential applications in a wide range of applications where fast and accurate real time humidity control is required.
- polymer FBG sensor
- humidity sensors
- etched gratings
Rajan, G., Noor, Y. M., Liu, B., Ambikairaja, E., Webb, D. J., & Peng, G-D. (2013). A fast response intrinsic humidity sensor based on an etched singlemode polymer fiber Bragg grating. Sensors and Actuators A : physical, 203, 107-111. https://doi.org/10.1016/j.sna.2013.08.036