Calibrating unit for calibrating a hydraulic or electric pressure gauge, especially of a probing device
A calibrating unit for calibrating a pressure gauge includes a piston (7) which may be loaded by pressurized oil and which may be fastened at its upper end to the pressure gauge. A pressure piece (11) being movable within the piston (7) can be loaded at its upper side by a measuring member (3) of the pressure gauge and can transmit this load at its lower side to a spring system (15,16,17) resting on the housing (6) of the unit. The movement of the pressure piece (11) is determined by a measuring instrument such as a measuring watch (21). The deflection of the pointer of this watch is a calibrating measure for the pressure gauge.