ABSTRACT The present work deals with the development of low cost, appreciably accurate precision electronic circuit for resistive sensor where measurement of the incremental resistance change with high degree of accuracy is essential. A linear and sensitive active half 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 half bridge circuit and two times more sensitive than full Wheatstone bridge circuit. Studies have also been made to analyze the errors due to ambient temperature, connecting lead resistance and dc excitation voltage. Experimental results show that output of the circuit has negligible effect on ambient temperature and connecting lead resistance. The error due to excitation voltage has been compensated using Artificial Neural Network (ANN) based inverse modeling technique.
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nullS. Khan and T. Islam, "Precision Active Bridge Circuit for Measuring Incremental Resistance with ANN Compensation of Excitation Voltage Variation," Journal of Sensor Technology, Vol. 1 No. 3, 2011, pp. 57-64. doi: 10.4236/jst.2011.13008.
 M. Rehman. and V. G. K. Murti, “A New Method for In-Circuit Resistance Measurement,” Journal of Physics E: Science and Instruments, Vol. 17, 1984, pp. 445-446.
 M. Rehman, M. T. Ahmad and M. Arif, “Critical Study and Applications of a Self-Balancing Bridge,” IEE Proceedings, Vol. 137, No. A(1), 1990, pp. 23-26.
 Z. M. Rittersma, “Recent Advancements in Miniaturized Humidity Sensors―A Review of Transduction Techniques,” Sensors and Actuators A, Vol. 96, 2002, pp. 196-210. doi:10.1016/S0924-4247(01)00788-9
 Doeblin, “Measurement Systems Application and Design,” Tata McGraw Hill, Noida, 2002.
 Per Holmberg, “Automatic Balancing of ac Bridge Cir-
 cuit for Capacitive Sensor Elements,” IEEE Transactions on Instrumentation and Measurement, Vol. 44, No. 3, 1995, pp. 803-805. doi:10.1109/19.387337
 J. Fraden, “Hand Book of Modern Sensors, Physics, Design and Applications,” 3th Edition, New York, 2003.
 S. Poussier, H. Rabah and S. Weber, “Smart Adaptable Strain Gauge Conditioner: Hardware/Software Implementation,” IEEE Sensors Journal, Vol. 4, No. 2, 2003, pp. 252-267.
 A. J. Lopez-Martin, J. I. Osa, M. Ziza and A. Carlosena, “Analysis of a Negative Impedance Converter as a Temperature Compensator for Bridge Sensors,” IEEE Transactions on Instrumentation and Measurement, Vol. 52, No. 4, 2003, pp. 1068-1072.
 A. P. Singh, S. Kumar and T. S. Kamal, “Virtual Compensator for Correcting the Disturbing Variable Effect in Transducers,” Sensors and Actuators A, Vol. 116, 2004, pp. 1-9. doi:10.1016/j.sna.2004.03.048
 G. A. L. Araujo, R. C. S. Freira, J. Silva, S. Y. C. Catunda and G. Fontgalland, “DC-Amplifier Input Offset Voltage Control in a Constant Temperature Thermo- Resistive Sensor Measurement Instrument,” IEEE Transactions on Instrumentation and Measurement, Vol. 56, No. 3, 2007, pp. 778-783.
 T. K. Maiti, “Development of a Lead Resistance Compensation Technique for Remote Variable Resistive Sensors,” Measurement Science and Technology, Vol. 17, 2006, pp. 1424-1427. doi:10.1088/0957-0233/17/6/021
 T. K. Maiti and A. Kar, “A New Concept of Theory and Technique for Remote Strain Measurement,” Sensor & Transducer Journal, Vol. 77, No. 3, 2007, pp. 1045- 1050.
 K. F. Anderson, “The New Current Loop: An Instrumentation and Measurement Circuit Topology,” IEEE Transactions on Instrumentation and Measurement, Vol. 46, No. 5, 1997, pp. 1061-1067. doi:10.1109/19.676711
 E. Rubiola, C. Francese and A. De Marchi, “Long-Term Behavior of Operational Amplifiers,” IEEE Transactions on Instrumentation and Measurement, Vol. 5, No. 1, 2001, pp. 89-93. doi:10.1109/19.903883
 S. Pradhan and S. Sen, “An Improved Lead Compensation Technique for Three-Wire Resistance Temperature Detectors,” IEEE Transactions on Instrumentation and Measurement, Vol. 48, No. 5, 1999, pp. 903-905.
 D. H. J. Baert, “Circuit for the Generation of Balanced Output Signals,” IEEE Transactions on Instrumentation and Measurement, Vol. 6, 1999, pp. 108-110.
 T. Islam and H. Saha, “Study of Long-Term Drift of a Porous Silicon Humidity Sensor and Its Compensation Using ANN Technique,” Sensors and Actuators A: Physical, Vol. 133, No. 2, 2007, pp. 472-479.
 A. Khan Shakeb, D. T. Shahani, and A. K. Agarwala, “Sensor Calibration and Compensation Using Artificial Neural Network,” Transaction of Instrumentation, System and Automation Society, Vol. 42, No. 3, 2003, pp. 337-352.