Showing papers by "Tarikul Islam published in 2008"

A sensitive detection electronics for resistive sensor

Abstract: Present work deals with the development of a low cost, appreciably accurate precision electronic circuit for resistive sensor where measurement of the incremental resistance with high degree of accuracy is essential. A linear and sensitive active bridge circuit requiring only few components for its hardware implementation has been proposed for measuring very small resistance change due to change in physical quantity or chemical analytes. Theory of the proposed active bridge circuit has been discussed and experimental results have been compared with conventional bridge circuit. Initial measurements are made with Pt-100 Strain gauge sensor but it can be extended to other resistive sensors of practical importance. Results show that the active bridge circuit is almost four times more sensitive than conventional full bridge circuit.

Study of cross- sensitivity of porous alumina based trace moisture sensor in dry gases

Abstract: Present work deals with the development of capacitive porous alumina based trace moisture sensor in the range of 50 to 500 ppm(V) fabricated by low cost sol-gel technique. For its commercial usefulness, the cross-sensitivities due to the presence of organic vapours like ethanol, methanol, acetone and benzene are studied. The effects of ambient temperature have also been studied. Experimental results show that moisture sensor is responsive to the polar organic vapours but has almost negligible response to the nonpolar molecules like benzene. However compared to the moisture sensitivity, the sensor response to the organic vapours is very small.