Terracon Consultants used a Dipstick 2272 floor profiler to verify a small concrete mounting pad was microflat. A 3-D elevation survey was performed using a series of parallel runs spaced 1 foot apart with individual elevation measurements spaced 1 foot apart on each run.
Fig. 1 The initial reference run was performed across the top; each parallel run was 1 foot apart. Contour elevations are in millimeters.
Fig. 2 A 3-D view of the slab. The two significant depressions in dark green at right represent floor drains. The contours are in millimeters.
Fig. 3 Elevation data of the test area showing the locations and variations in millimeters of each data point collected during the survey. The red-outlined square and circle are the floor drains.
Fig. 4 Comparative section profiles after each grind-and-fill operation. Section 4-1 is the initial slab profile. The two repair attempts (Sections 4-2 and 4-3) showed improvement, but the final attempt (Section 4-4) decreased quality even more than the initial contour.