The water level tube is a simple measuring instrument used for height alignment of two distant points in space when the distance does not allow the use of a spirit level.

It consists of a long, flexible, transparent plastic tube filled with water. For the height alignment of one point with another, one end of the tube is placed vertically so that the water level is exactly at the first point. The other end is placed at the point where alignment is desired, and the water level at the second end will be at the same height as that of the first end.

Conditions for the proper functioning of the instrument are:

• The water to be at the same temperature throughout the length of the tube.
• The tube to contain no air bubbles.
• There must be no obstruction along the tube.

The use of the water level tube is based on the principle of communicating vessels. Therefore, the water level at the two ends of the tube is always on the same line, regardless of the length of the tube.

Dimensions:

• Inner diameter: 6mm, Outer diameter: 9mm
• Inner diameter: 8mm, Outer diameter: 12mm
• Inner diameter: 10mm, Outer diameter: 14mm