How often should you check a rotating laser?
We would recommend that site staff should check a rotating laser for accuracy every week. This site check should also be logged and stored with the Calibration Certificate for the rotating laser. Any deterioration in the accuracy of the rotating laser can then be easily identified and the rotating laser can be serviced and calibrated.
Why you should check your rotating laser weekly.
Using any piece of equipment that you haven’t checked could lead to disaster. Using a rotating laser that hasn’t been checked can lead to a costly mistake. Take the case of steel erecting sub-contractor who started off putting up steel columns for a new steel frame garden centre building. He reported to the main contractor that some of the concrete bolt bases were high, so the contractor surveyed all the bases to find some of them to be no more than 5mm high and the contractor remedied the bases. The steel erector sub-contractor continued erecting the steel frame building and after putting up more than 20 columns and the connecting beams he paid a visit to the contractor once more to notify them that next concrete base was so low that they couldn’t even fit it to the bolts. The main contractor checked the base and found that it was at the correct level. Then main contractor’s site engineer then performed a simple two peg test on the Leica rotating laser to find that it was falling at a rate of over 1mm every metre. The sub-contractor protested that he had a calibration certificate and that it should be right, but finally had to admit that his rotating laser was not fit for purpose. After a full survey of the erected columns, the steel erector had to adjust at least 50% of the steel already erected, causing him lost time of 5 days that he couldn’t recover.
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.
Get your Rotating Laser Calibrated.
If, having checked your rotating laser and you find that it is not giving the accuracy required then you should get it calibrated. Your local preferred survey supplies specialist will offer to service, adjust and calibrate your rotating laser. This will be more cost effective than continuing to work with a rotating laser giving out poor inaccurate levels.
Top Tip for Getting the Best Results When Checking Levels.
Whenever you are checking an Automatic (Dumpy) Level, or a Rotating Laser 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.