FEM consists of 3 types of portable microprocessor-based fuel efficiency monitors. They are as cited below: FEM-1 measures %O2 and C. FEM-2 measures O2, °C and CO. FEM-5 measures O2°C, CO, SO2, NO & NO2. The microprocessor calculates values of percentage combustion efficiency i.e. net & gross, percentage carbon dioxide and percentage excess air for types of...