smartGAS introduced the new smartMODUL-FLOW sensor, which can detect sulphur dioxide (SO2) in the concentration range of 0 to 2,000 ppm. The toxic gas, which is responsible for the so-called acid rain, is formed in combustion processes of fuels with a high concentration of sulphur. During the last years the emission of SO2 into the atmosphere has been reduced due to the use of fuels with less sulphur and the integration of flue gas cleaning systems in power plants. Today one of the largest emitters of SO2 is shipping, where fuel with high sulphur concentrations is still quite common. The new sensor can be used to monitor SO2 concentrations in small unit power stations or industrial plants. It is also ideally suited for any other application, where SO2 could be released into the environment. A typical example is the food packaging industry, where SO2 is used as preservative. The sensor utilises infrared (NDIR) absorption and shows nearly no cross sensitivities with other gases. Due to the dual-beam-technique the sensor shows practically no aging or long term drift. The OEM sensor is available with many standard interfaces like Modbus ASCII with RS485, UART or 4...20 mA enabling an easy integration into existing control architectures.