ZORN Mini | Light Weight Deflectometer

Creative solution in proven quality. ZORN Lightweight Deflectometers are valued equally by leading construction companies and supervisory authorities. For many years they have also been used in the broadband deployment area. The ZORN MINI now makes it possible to test reliably the compaction of the backfill material also with new cost-saving methods.

A small device for a large task. Cable trenches for broadband fibre optic cable are often narrower and shallower than those for conventional supply cables. Nevertheless, the quality of the compaction must be correct during the filling of the trenches. Conventional falling weight deflectometers are too large for a test and therefore unsuitable.

With the ZORN MINI a Lightweight Deflectometer specially developed for this application is now available to construction companies and their contractors. Based on the proven test specification TP BF-StB, Part B 8.3, users can reliably test the compaction from a trench width of 120 mm using this device.

New challenges demand appropriate skills. The loading plate for the ZORN MINI has an oval shape and with a minimum width of 100 mm matches the geometry of a narrow fibre optic cable trench. The area of the plate is the same as that of a conventional Light Weight Deflectometer with a round loading plate of 150 mm diameter. The maximum normal stress under the loading plate of the ZORN MINI is 0.2 MN/m2.

Also while backfilling narrow fibre optic cable trenches, courses of material are generally applied in layers and compacted. The course thicknesses of 150–200 mm are less than during conventional road openings. The ZORN MINI is equipped with a 5 kg falling weight matched to these conditions. The impact force generated with this falling weight of 3.535 kN is optimal for testing these courses.


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