Gas Detection using Low-Cost Resistive Sensors

A new electronic gas detection system is presented in this paper. It is particularly important to pay attention to electronic noses that employ several resistive sensors. Due to new materials (TiO2) or low-cost fabrication processes, new resistive sensors may be extremely valuable, and if these sensors are combined with traditional ones (SnO2), a novel instrument will be needed to manage high-value resistive sensors ranging from kilohms to ginghams. Modular hardware is proposed that uses an improved resistance-to-period converter, where sensors are powered by DC. Under the assumption of commercial resistors, the relative standard deviation over six decades is below 0.01% and the relative displacement from the reference line is less than 1%. Using eight sensors, the prototype detects and estimates substance concentrations, and communicates the results on the Internet.