“…However, MRGO 12H sensor had outstanding response and recovery time superior to PRGO 12H and NRGO 12H, thus indicating superior material selectivity towards sensing LPG compared to NRGO 12H and PRGO 12H. While reports have been made on how high operating temperature of sensors results in reduced response time and large recovery time, 28 at a low operating temperature of 30 °C, we have obtained response time that are far below reported values in several literature 9,37,39,40 while recovery time of the The time required for MRGO to attain peak resistance at a concentration of 150 ppm is about 1710 seconds while NRGO required a time of about 1949 seconds and 3016 seconds was required in the case of PRGO as shown in Table 3. Thus, MRGO 12H sensor had a lower sensing period for the same concentration compared to PRGO and NRGO.…”