About compressor efficiency: volumetric efficiency is the actual capacity of the compressor and the theory of the ratio of gas volume, expressed as a percentage. Quantitative gas compression efficiency is compressed to the ratio of the actual's theory of power and the power needed. The theory of power according to working condition of isothermal or adiabatic condition to calculate. The corresponding percentage compression efficiency can be used to determine and presentation. In terms of a compressor driven by steam drive or internal combustion engine, mechanical efficiency refers to the compressor indicated work points and on the shaft brake horsepower Ma Lizhi ratio. In the case of a compressor motor drive, mechanical efficiency refers to the indicated power compression cylinders with the ratio of the shaft power of compressor. In percentage terms.