The EK205 is a battery-operated volume conversion device that can be easily mounted onto gas meters from Elster or other manufacturers. Powered by a lithium battery for a minimum five-year service life, the device calculates gas volume at base conditions on the basis of consumption data supplied by flow-proportional pulses from the connected meter and the measurements of gas temperature and pressure. The data logging function, serial interface and different data communication protocols allow integration in head-end and Supervisory Control and Data Acquisition (SCADA) systems.