This apparatus demonstrates the relation between pressure and volume of a gas at constant temperature using pressure from an outside supply.
The equipment consists of an acrylic tube sealed on top and bottom and attached to a stand. Pressure gauge, vent valve is fitted to the top of the tube while water supply and drain valves are fitted to the bottom. Water level in the tube determines volume of the air column. Corresponding pressure is indicated on the pressure gauge. The apparatus requires an outside water supply.