Mitra Djamal
Technology development encourage many the waste on the environment, one of them is a gaseous waste. The gaseous waste in the air consists of various chemical compounds. The gaseous waste in the air usually contains particles of solid material, called particulate matter. For example, carbon monoxide (CO), carbon dioxide (CO2), sulfur oxide (SOx), ammonia (NH3), methane (CH4), chlorine (Cl2), etc. These gases are reactive chemical compound, when the gas is exposed to the body, the gas will react with many compounds, which can disrupt the normal body system. So we need gas sensors that can continuously and effectively detect toxic gases to avoid most of the dangers presented. In this research, a new gas sensor based on thermopile and acoustic method will be present. This sensor can detect toxic gas concentration. Thermopile can detect temperature changes that occur around it. Temperature changes are related to thermal conductivity of gas. If the thermal conductivity of gas is known, concentration of gas can be known. The acoustic method consists of speakers as a sound wave transmitter and microphone as receiver sound waves. The acoustic method aims to measure the speed of sound waves. In medium gas, if the speed of sound is known, the concentration of gas can be known. The purpose of this research is to build a gas sensor that can detect toxic gas concentrations. Thermopile, speakers and microphones used in this sensor are sold in the market with a relatively cheap price, so the production cost of the manufacture of the sensor is cheaper than the commercial gas sensor.