Total means of absolute pressure at the standard discharge point. Nowadays, new units for pressure are Pascal, named after the scientist; Blaise Pascal, whose unit is introduced in the metric system to be the most precise.
In most specifications pressure is being expressed in gauge values and marked with "g" between brackets, however it should be expressed in absolute figures, because at mountain level, the suction pressure will be lower than the absolute pressure of 1 bar, which would result in another pressure ratio. During the selection of the air compressor one must be made aware of this phenomenon. For oil free rotary compressors above 1000 m, air has a low suction pressure, but also low specific weight, which causes low efficiency and high discharge temperature. For compressors in mountainous areas please contact our engineering department.