Hydraulic pressure gauges are mainly used to measure the pressure of liquid medium in the hydraulic systems. The tube expansion causes travelling of the tube end. After the transfer and the amplificaton by the movements and rods, the pointer will indicate readings in the scale of the gauges. The hydraulic pressure test meter can be used in various complicated circumstances. Diaphram devices can be added to assist the pressure measurement of the special oils with high viscocity, easy crystallization, easy consolidation, and granule contenting.
On most presses, the maximum pressure will be no more than 200 bar or 3,000 psi.
Hydraulic press are reliable and accurate because they are based on Pascal's law which says that: Pressure on a confined fluid is transmitted undiminished and acts with equal force on equal areas and at 90 degrees to the container wall."
So for example, our hydraulic pressure gauge says 1000 PSI or pounds per square inch, that 1000 pounds per square inch is applied to 10 square inches. This means that each square inch of surface area is applying 1000 pounds of force and there are 10 square inches giving us a total of 10,000 pounds of force.