In this video you will learn how to use a Spirit Level.
A Spirit Level consists of two or three tubes filled with a liquid such as ethanol and a single bubble of air suspended in the opposite direction from gravitational pull.
To use the Spirit Level, place it on the surface whose level you would like to check. Wait for the bubble to settle and ensure that it is properly centered in the tube. If the bubble is not centered, make adjustments until it indicates a level surface. You can do this by varying the thickness of mortar or by applying pressure on the brick with your hands or a trowel.
Change the position of the Spirit Level to make sure that it conveys an accurate reading.
When measuring the comparative level between two distant objects beyond the reach of the Spirit Level, you may place it on top of a Straightedge to bridge the gap. If the bubble indicates an uneven surface, remove the Straightedge and Spirit Level and make necessary adjustments before taking a second reading.
Make sure that you take your reading from a right angle in order to avoid error.
You have now learned to use a Spirit Level.