The liquid level is used in the construction business, as a rule, for check of horizontal position of parts or surfaces. However, it is easy to extend the spirit level, entrusting him and check the verticality. It’s enough to carry its body in the form of a right triangle. Then the Central position of the vial and the capsule, depending on the choice of support surface to confirm either its horizontal or vertical position.
For the housings you will need two identical triangular plates, carefully sawn from a Board thickness 15 — 20 mm. the Mutual perpendicularity of the sides should be designed with the utmost precision. In parallel, one of them in each half of the casing is cut a rectangular window with semi-circular cavities on the ends.
The capsule itself can be made of cut glass tubes, sealed tubes first with one and after filling the required number of colored distilled water on the other side.
The Assembly level is that you install the capsule between the halves of the nests of the Windows with rubber gaskets. It will protect the tool from premature failure and ensure the possibility of adjusting the position of the capsule by using the adjusting screw, mounted in a countersunk hole in the junction of the case halves.