A spirit level, bubble level, or simply a level, is an instrument designed to indicate whether a surface is horizontal (level) or vertical (plumb). It is called a "spirit level" because the liquid inside its vial is commonly alcohol, or "spirit". The name refers to this alcohol-based solution, which, along with an air bubble, indicates whether a surface is level or plumb. Alcohol was historically preferred over water because it has a wider temperature range, won't freeze, and provides less friction for the bubble, ensuring greater accuracy and longevity of the tool. Two basic designs exist: master level and frame level.
A precision frame spirit level mainly used to inspect the straightness of various machine tools and other equipmentusing, the working principle is based on the flow of liquid and the level of the liquid surface, it is a spirit level to directly display the minute angles of inclination relative to horizontal and vertical positions, functioning as a square universal angle measuring instrument. It is made of high-quality special cast iron and features a prismatic (150°) and a flat measuring surface. The measuring surfaces are finely ground, and the spirit level is equipped with a ground longitudinal level made of glass, a transverse level, and full heat protection.
A precision master spirit level is a universal angle measuring instrument that uses the principles of liquid flow and the level of the liquid surface to directly show angular displacement with a bubble vial, measuring small angles relative to the horizontal position. It also called bench level commonly used by machinists. It consists of a V-shaped bottom plane and a spirit level, and is used to detect the levelness of a plane, small tilting angles, and equipment installation calibration. This tool is widely used in machining, construction, equipment debugging, and other fields.
How to Use
During measurement, put the working surface of the level close to the surface to be tested. Wait till the bubble is stationary, then take the reading. The scale value shown by the level is the inclination on 1m. To measure the actual inclination of length L use the formula below:
Actual inclination=scale reading x L x number of deviating division.
For example: scale value=0.02mm/m. L = 200mm
Number of deviating division = 2 division
Actual inclination= 0.02/1000 x 200 x 2 = 0.008mm
To avoid the inaccuracy of the zero position of the level, which causes the error during measurement, the zero position of the level must be checked or adjusted before use.
Check and adjust
First clean the working surface and place on stale platform, put the level on an approximately horizontal flat plate which should has a firm foundation. After the bubble is stationary, set one end, for example, the left end(the observe facing the level) at zero. Make an 180° turn. Again put the level on the flat plate at the same position. After the bubble is stationary at the same end(left end), take a reading of “a” divisions(former zero reading as a starting point). Then the zero position error of the level is a/2 division.
If the level is found not correct at zero, adjustable level can be adjusted according to the standard procedure:
(1) Open the round cover plate in the hole and use a special spanner to lightly rotate the adjusting nut(see drawing 1)
(2) Ajust 120° the adjusting screws(see Drawing2)
When the air bubble is stable, remember the reading number; turn the level by 180° and place it back to its original position and observe again the reading. If the difference of the two readings is not over 1/2 line, it means the adjustment is correct, then put back the round cover plate and wait for 2-4 hours more. If there is no change, the level can be put into use. Do not turn the screw or not which is not intended for adjustment purpose. Tighten up the nut after the adjustment.
Polish working surface can help to adjust zero position of the fixing type level.
Different types of spirit levels may be used by carpenters, stonemasons, bricklayers, other building trades workers, surveyors, millwrights and other metalworkers.
For more specification of spirit levels, please visit our spirit level product.
