*2.2. Measurements Procedures*

Figure 2 illustrates the engine test bed layout. The sensors arranged on the test bed are: in-cylinder pressure sensors, inlet pressure and temperature sensors, exhaust pressure and temperature sensors, air flow meters, hydraulic dynamometer, etc. The fuel flow measurement in the test bed uses the weighing scale and clock with a two-position three-way valve instead of a flow meter, which is a traditional method but ensures the accuracy of the fuel flow measurement.

**Figure 2.** Schematic diagram of engine test bed layout.
