The proving ring is a device used to measure force. It consists of an elastic ring of known diameter with a measuring device located in the center of the ring. Proving rings come in a variety of sizes. They are made of a steel alloy.
A Hydraulic load cell is a type of mechanical load cell and it has a piston-cylinder arrangement that uses a liquid medium under pressure in a confined space which also makes it a force-balance device.
Its main parts are;
A diaphragm: The diaphragm is a thin circular plate used to measure low and high pressure, force or load based on the principle of deflection. Also corrugated diaphragms are used in order to improve the load cell sensitivity and the materials they are made from are stainless steel nickel and phosphor.
A piston: A piston with a loading platform(usually a thick machined steel distribution plate) placed on top of the diaphragm,
A liquid medium (Water or oil) and
A bourdon tube pressure gauge.