Single Limb well Type direct reading Manometers are used for precision measurement of pressure, vacuum, differentials pressure flow and liquid level measurement. Initially liquid is filled in the well till the scale shows zero but when a positive pressure is being applied on the liquid in the well, causing the level to go down very slightly. Liquid level in the indicating tube has risen substantially giving direct reading from scale in desired units. The single limb well type manometer is accurate & dependable as well as highly versatile for many applications. All Scales are graduated to correct for the drop in the well level.