(ϱmhm – ϱy)g represents pressure difference in a manometer system for measuring level measuring, where ϱm is the density of manometric liquid and hm is the level of manometric liquid.

Load cells are force measuring devices, and they are used for a level to force conversion.

Float elements are used for measuring the liquid level of a system. Liquid level indication is obtained using displacement of float element.

When float made lighter, errors due to density variation decreases.

While using the float element, liquid of uniform density distribution is not required. But in the displacer system, liquid with constant density distribution is important.

Pressure at top of the container in a closed container system is the pressure above liquid level which is the pressure of vapor.

Diaphragm elements are used for measuring pressure and they are used for a level to pressure conversion.

In a liquid column with constant density ‘ϱ’, pressure can be represented as a product of density, acceleration due to gravity and height of the liquid column.

Liquid used for a level to force conversion should have constant density distribution at all points, it enables consistent measurement of force.

Displacer systems are in which weight of float will be greater than the weight of liquid to be displaced.