Explain the working and principle of dead weight tester.
Dead weight tester:
Principle: It works on the principle that the downward force of the weight on the top of the piston is balanced by the pressure exerted by the fluid beneath the piston
Working: For calibration purpose, first a known (calculated) weight is placed on the platform and the fluid pressure is applied on the other end of the piston until enough force is developed to lift the piston-weight combination and the piston floats freely within the cylinder when the fluid gauge pressure equals the dead weight divided by the piston area.