Implementation of linear trace moisture sensor by nano porous thin film moisture sensor and NLAmp

Almost all type of moisture sensors has a non-linear response. With out linearization it is difficult to apply such a non-linear sensor in electronics circuits, specially in analog electronics. Non linear sensor and transducers characteristic can be linearized using analog electronics or digital electronics. In this paper a method of linearization of such non-linear sensors characteristics using analog electronics is described. Theoretical explanation of the methods and its verification by experiment is stated in this paper. It may possible to linearize any non linear characteristic using this method. We use thin film nano porous trace humidity sensor as a non linear device for the circuit justification. The fabrication process of the sensor is also described in this paper.

[1]  M. Radhakrishna,et al.  Characterization of Al2O3 thin films prepared by spray pyrolysis method for humidity sensor , 2007 .

[2]  K. P. Biju,et al.  Sol–gel derived TiO2:ZrO2 multilayer thin films for humidity sensing application , 2008 .

[3]  J Yang,et al.  Influence of binders on the sensing and electrical characteristics of WO3-based gas sensors , 1999 .

[4]  K. Sengupta,et al.  Pore size optimisation of humidity sensor—a probabilistic approach , 2002 .

[5]  Zbigniew Moroń.  Can analog circuits still increase sensors smartness , 1998 .

[6]  J. Mooi,et al.  The origin and types of pores in some alumina catalysts , 1968 .

[7]  K. Watanabe,et al.  A digital hygrometer using a polyimide film relative humidity sensor , 1996 .

[8]  Hiranmay Saha,et al.  A hygrometer comprising a porous silicon humidity sensor with phase-detection electronics , 2003 .

[9]  K. Nishio,et al.  Fabrication of Nanoporous WO 3 Membranes and Their Electrochromic Properties , 2003 .

[10]  P. Ratnasamy,et al.  Catalytic Aluminas: Surface Models and Characterization of Surface Sites , 1978 .

[11]  Development of commercial nanoporous trace moisture sensor following sol–gel thin film technique , 2008 .

[12]  J. Nevin,et al.  A polyimide-based capacitive humidity sensor , 1985, IEEE Transactions on Electron Devices.

[13]  P. Su,et al.  Novel flexible resistive-type humidity sensor , 2007 .

[14]  Bulent E. Yoldas,et al.  Alumina gels that form porous transparent Al2O3 , 1975 .

[15]  R. K. Kotnala,et al.  Microstructure-dependent humidity sensitivity of porous MgFe2O4–CeO2 ceramic , 2007 .

[16]  Ap Shivaprasad,et al.  Microprocessor-based temperature indicator using platinum resistance as the sensor , 1987 .

[17]  P. Hesketh,et al.  Rapid, reversible, sensitive porous silicon gas sensor , 2002 .

[18]  Xiujian Zhao,et al.  Sol–gel fabrication of compact, crack-free alumina film , 2007 .

[19]  Noboru Yamazoe,et al.  Ceramic humidity sensors , 1983 .