An Electronic System to Heat MOX Sensors With Synchronized and Programmable Thermal Profiles
Authors: Depari A., Flammini A., Marioli D., Sisinni E., Comini E., Ponzoni A.
Autors Affiliation: Univ Brescia, Dept Informat Engn, I-25123 Brescia, Italy;
Univ Brescia, CNR IDASC SENSOR Lab, I-25123 Brescia, Italy;
Univ Brescia, Dept Chem & Phys, I-25123 Brescia, Italy
Abstract: Metal oxide (MOX) sensors are widely used in several application fields: environmental monitoring, home automation, food control, and so on. Research activities in this topic are oriented toward new materials and nanotechnologies, thus requiring new instruments for the sensor characterization and management. Often, in order to improve selectivity, sensitivity, stability, the sensor is heated according to purposely designed profiles. The repeatability of the measurement conditions strongly depends on the ability to perform a sensor resistance measurement in a synchronous fashion with respect to the imposed thermal profile. This work proposes an electronic equipment for a complete management of a generic MOX sensor. The system is able to estimate the sensor resistance in a range varying from tens of kilohms up to tens of gigohms, while driving the sensor heater with a thermal profile designed by the user. Thanks to the short readout time (10 ms) and to the synchronism between the heater management and the sensor resistance measurement, the system is suitable for monitoring fast transients and thermal dynamics of the sensors. In addition, an estimation of the sensor parasitic capacitance, modeled in parallel with the resistive part and on the order of few picofarads, is provided for diagnostic purposes. Experimental results conducted on both commercial resistors/capacitors emulating the sensor, and on a real SnO2 nanowire-based sensor for carbon monoxide detection have demonstrated the validity of the proposed approach. Broad topic: 17. Measurement Techniques.
Journal/Review: IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
Volume: 61 (9) Pages from: 2374 to: 2383
KeyWords: GAS SENSORS; AC MEASUREMENTS; DOI: 10.1109/TIM.2012.2199192Citations: 7data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2022-01-23References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here