Portable and Room Temperature Operating H2S Gas Detection and Alert System Using Nanocrystalline SnO2 Thin Films

Portable, compact, wireless, and hand-held electronic alarms which can detect hydrogen sulphide (H2S) gas at room temperature from 1 to 40 ppm is fabricated using nanostructured tin oxide (SnO2) thin film deposited on quartz using the Langmuir Blodgett technique. It was demonstrated that SnO2 thin film with gold contacts works as a chemiresistive, selective, and sensitive sensor for H2S gas at room temperature. Few SnO2 thin films were studied for extracting the sensitivity and accuracy parameters of the sensor. Using the optimized parameters, an electronic alarm with less than 5 V input power requirement was fabricated to make it inherently safe for explosive environments. Specificity, reliability and stability studies of the sensors showed satisfactory performance for using these sensors for monitoring H2S leak. Along with the 3-D printed light weight gas sensor housing, it makes a hazard free, compact, reliable, and versatile sensing device.