The water level tube is a simple measuring instrument used for the vertical alignment of two distant points in space, which are at such a distance that the use of a spirit level is not feasible.

It consists of a long, flexible, transparent plastic tube filled with water. For the vertical 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 of the tube is placed at the point where the alignment is desired. The water level at the second end will be at the same height as the water level at the first end.

Conditions for the proper functioning of the instrument are:

• The water must be at the same temperature along the entire length of the tube
• The tube must not contain air bubbles
• There must be no obstructions along the tube

The use of the water level tube is based on the principle of communicating vessels. Therefore, the water level at both 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