Spirit Level or Bubble Level
What is a spirit level
A spirit level is a tool designed to indicate whether a surface is level or horizontal to the ground. It is also used for checking if a surface is plumb or vertical.
The spirit level is also called a bubble level. It uses a vial partially filled with a colored liquid (mineral solution) leaving a bubble in it. The bubble sits in the center of the vial when it is perfectly horizontal.
How are spirit levels made
A spirit level consists of a vial containing liquid which is encased and mounted on a base.
The vial is shaped like a barrel, rectangular block or slightly curved (banana shaped) barrel. The vial is mostly made of acrylic.
The base is made of aluminum, steel, plastic, wood etc. It may have magnetic face which is useful in sticking it to a steel surface.
Some levels have digital readouts, that is, a display that reads the measurements of the surface you are levelling. It provides more precise measurement as it is easier to read than the vial level.
What liquid is used in a spirit level
The colored liquid used in the vial of a spirit level is alcohol, such as, ethanol rather than water. Alcohol has low viscosity (less sticky) and surface tension. This allows the bubble to move freely in the vial.
How to check accuracy of a spirit level
To check the accuracy of the spirit level, place the level on a surface and note the location/reading of the bubble. Then rotate the level end to end by 180 degrees and place it in the same location. Note the location/reading of the bubble. If it is the same on rotating the level by 180 degrees, then the level is accurate. If not, the level needs to be calibrated.
To check the accuracy of vertical vial, follow the same procedure as above against a vertical surface.
How to calibrate a spirit level
The encasement of the vial is screwed to the spirit level assembly. The level is calibrated by adjusting the screws.
However, it is important to note that before adjusting the vials, the spirit level must be placed on a perfectly horizontal (level) surface. Once the screws are adjusted so that the bubble is in the middle, the level is calibrated.
Who uses spirit levels
Spirit levels are used by several tradesmen, such as, building contractors, carpenters, cabinet installers, masons, plumbers, electricians, woodworkers, and do-it-yourselfers, such as homeowners.
What type of spirit level do I need
A six inch to a foot long torpedo level is useful for small jobs or while working in a tight space, such as, plumbing etc. Some models have a magnetic face for sticking to metal surfaces, such as, metal pipes etc.
A one and a half to two-foot level is useful for most of the general-purpose levelling like hanging picture frames and shelves, installing cabinets, woodworking, and DIYers projects around the home.
