How to check a Rotating Laser Level for Accuracy.

Topcon RL-H5A rotating laser level

This article contains a guide on how to check a rotating laser level for accuracy.

Checking a Rotating Laser level for accuracy uses the same principle as checking the accuracy of a dumpy or Automatic Level. The principle of which is, that we should have the same height difference of two points when measured from different positions and different lengths of sight.  However, due to the rotating nature of the laser, there are more steps involved for the rotating laser check than the standard two peg test for checking a dumpy level or an Automatic Level.

Remember that before setting up any rotating laser on a tripod, especially when checking for level accuracy, it is important to know that the tripod you are using is in good condition.  A test for the tripod can be found on the page test your tripod. The video below shows a tripod in poor condition.

Keep reading for the information on how to check a rotating laser level for accuracy.


Top Tip for Getting the Best Results When Checking Levels.

Whenever you are checking a rotating laser level, or an Automatic (Dumpy) Level, or a Total Station, make sure that the tripod head is as close to being level as possible. Whenever I am carrying out these checks I like to use a bullseye spirit level like this one I bought from Amazon. Its 65mm diameter so it spans the tripod access hole and is large enough to be easy to set.

Large Bullseye Spirit Level
65mm Large Bullseye Spirit Level.

The Procedure of how to check a rotating laser level for accuracy.

First, setup your tripod on a firm and sturdy surface, one that will support the weight of the tripod and rotating laser and also an area not subject to vibrations from plant and machinery.  Ensure the top of the tripod is level, use a spirit level if needed.  You should choose a position for the tripod that is close (1m to 2m from the rotating laser/tripod) to a suitable upright surface that can be marked on and another suitable upright surface ideally over 30m away. 

How to check a rotating laser level for accuracy. Stage 1 of a rotating laser check
Step 1 of the Rotating Laser Level Check

Set the rotating laser on the tripod securely, square to the closest surface to be marked, and switch on and allow the laser to self-level and start up.  You will be turning the rotating laser 90degrees three times during the course of the test.  If you have a grade laser then ensure that the grades are set to 0% in all directions before attempting to carry out any checks.

How to check a rotating laser level for accuracy. Stages 2 of a rotating laser check
Step 2 of the Rotating Laser Level Check

With the rotating laser switched on you are ready to take some measurements.  Turn on the receiver unit and select the fine tolerance setting for taking all the readings.  Place the receiver on the upright surface (wall), or using an E-Grad Staff in good condition, and move up and down until the receiver is at the given level.  Mark the wall with a suitable horizontal line or note down the reading take on the E-Grad Staff.  Now move to the other wall that is ideally over 30m away in either the opposite or perpendicular direction and place the receiver on the wall or staff and move up and down until the given level is achieved.  Mark the wall with a suitable horizontal line or take a reading on the staff.

How to check a rotating laser level. Stages 3 of a rotating laser check
Step 3 of the Rotating Laser Level Check

Return to the rotating laser and turn off the laser.  Without moving the tripod, release the fixing screw enough to allow the laser to be rotated through 90 degrees.  Switch the rotating laser back on and let it carry out its self-levelling procedure.  Turn on the receiver unit and select the fine tolerance setting for taking all the readings.  Place the receiver on the upright surface (wall), or using an E-Grad Staff in good condition, and move up and down until the receiver is at the given level.  This should be the same level as before, but if there is a difference note this down.  Mark the wall with a suitable horizontal line or note down the reading take on the E-Grad Staff.  Now move to the other wall and place the receiver on the wall or staff and move up and down until the given level is achieved.  Mark the wall with a suitable horizontal line or take a reading on the staff.  At this point you should have the same level (or difference in level if noted) marked as the previous round.  If there is a substantial difference in level (more than the specified manufacturer’s tolerance) then you should get the rotating laser serviced at your preferred survey equipment specialist.  If the levels taken are the same then you should repeat the above process a further two times to check all planes that the rotating laser works in.  If the rotating laser returns the same level each time then all is good.

How to check a rotating laser level. Stages 4of a rotating laser check
Step 4 of the Rotating Laser Level Check

Remember though to always ensure that you have your rotating laser calibrated at least every year to maintain its accuracy throughout its life.


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