What is water monometer?

As an AI language model, I assume you meant water manometer. A water manometer is a device used to measure the pressure of a gas. It consists of a vertical glass or plastic tube filled with water, with one end connected to the gas being measured and the other open to the atmosphere. The pressure of the gas pushes the water up the tube, which can be measured to determine the pressure. The height of the water column in the tube gives a direct measure of the pressure of the gas. Water manometers are commonly used in the medical and HVAC industries to measure pressures in systems like the respiratory system and air handling systems.