Level Survey for datum above sea level

How it’s performed
A reference point (master datum) is set on the construction site by a qualified engineer. Keeping that point as reference, the levelling survey is carried out by the engineer and an assistant using a dumpy level or digital levels (for high precision). The level is then transferred through the building for each storey and the measurements are directly recorded.
The horizontal level of the plane is measured by means of electronic laser methods and the measurements are shown on a digital display for digital levels. Digital levels provide higher levels of accuracy compared to traditional methods, and eliminate the chances of errors from manual measurements and interpolation of results.
When does a screed need the test?
The test is carried out before commencing screeding to check the accuracy of the substrate and to make sure that the designed floor zone can be achieved considering various aspects such as minimum, maximum and average screed depths, as well as insulation or acoustic products specified for the floor. This can help in estimating the right amount of materials required, and gives the opportunity to make an informed decision regarding any variations that can occur.