How to check a rotating laser?

How to check a rotating laser?

Here is a straight forward, easy to follow guide on how to check a rotating laser.  This is straight forward and can be done on any site by anyone.  It is a more detailed version of a two peg test that are used to check auto levels, like the Topcon AT-B4A.  If you are lucky enough to have a good site engineer, then he/she would be able to set up points of equal height, a good distance apart (over 50m) that can be used to quickly check any levelling instrument for accuracy.