34 it is also contemplated that hydraulic system 22 may be connected to multiple separate fluid tanks hydraulic system 22 also includes one or more pressure sensors 36 37 38 for example pressure sensor 36 monitoring an output pressure p of pump 24 may be provided in supply fluid passageway 62 when the fluid passes from pump 24 to hydraulic system 22 pressure sensor 36 in supply fluid passageway 62 monitors the output pressure p of the fluid supplied by pump 24 entering hydraulic system 22 and transmits an output signal reflecting the measured pressure to controller 70 the pressure sensor s 36 37 38 can be placed at any location suitable to determine a desired pressure of fluid supplied by pump 24 the exemplary calibration method described below determines output pressure p of pump 24 using pressure sensor 36 it is understood however that the calibration method may determine pressure p using pressure sensor s at other locations in hydraulic system 22 such as for example pressure sensors 37 38 as shown in fig2 pressure sensor 37 monitors a pressure associated with first chamber 50 of hydraulic cylinder 16 and pressure sensor 38 monitors a pressure associated with second chamber 52 of hydraulic cylinder 16 one skilled in the art will appreciate that pressure sensor 36 37 38 may include any pressure sensor assembly capable of ascertaining a pressure of the fluid supplied by pump 24 and or entering hydraulic system 22 furthermore the location s and number of pressure sensors 36 37 38 are not limited to the specific arrangement illustrated in fig2 controller 70 may embody a single microprocessor or multiple microprocessors that include a means for controlling an operation of hydraulic system 22 numerous commercially available microprocessors can be configured to perform the functions of controller.