Technical data sheet

Medium Heavy Falling Weight Deflectometer for the dynamic plate load test according to TP Gestein-StB, Part 8.2.1. For testing the soil and base courses applied using loads similar to traffic.


ZFG-M Mittelschweres Fallgewichtsgerät

Mechanical aspects

  • 15 kg loading device with ergonomically optimised ZORN triangular catch handle (calibrated impact force 14.140 kN, Evd measuring range up to 150 MN/m²)
  • 300 mm loading plate incl. acceleration sensor and mounting pin that can be repositioned
  • Maximum ground pressure 0.2 MN/m²
  • Testing depth max. 600 mm
  • All metal parts have high-quality zinc electroplating and in this way are optimally protected against corrosion and everyday wear and tear


  • Ergonomic handheld device made of robust plastic (Bayer polycarbonate Makrolon)
  • Power supply via 4 commercially available R6 batteries (Mignon/AA) for approx. 1500 tests (included) 
  • Multi-lingual, backlit, graphic display (German plus 10 other languages)
  • Easy to understand user prompts with indication of the deformation values during the test and automatic calculation of the results (deformation modulus Evd, M and s/v ratio) 
  • Graphic depiction of the measurement curves for easier interpretation of the results
  • Internal data memory for up to 10,000 tests plus SD card slot for external data storage 
  • Integrated calibration reminder
  • Integrated function check for the acceleration sensor
  • Text entry as required, e.g. for the improved assignment of the measurement locations, testers, course designations or material 
  • SD card reader (SD adapter to USB 2.0/USB OTG) 
  • Resilient full leather pouch for protection against dust and spray


  • GPS receiver with position information in the UTM or Gauss-Krueger format co-ordinate system
  • Quality thermal printer for print-outs directly on the construction site

Accompanying documents

  • Calibration record according to test specification TP BF-StB, Part B 8.4

Special note

  • Corresponding test standard exclusively as individual device.
  • Mandatory instruction by an employee from the manufacturer with hand-over record during delivery of the device

You can go back to the ZFG-M here

The dynamic plate load test with the Medium Heavy Falling Weight Deflectometer is used to check the soil and base courses applied using loads similar to traffic. A dynamic deformation modulus Evd,M is used as the measurement variable. The test is similar to the familiar method with the Lightweight Deflectometer (ZORN ZFG); with the difference that the maximum normal stress under the loading plate of the Medium Heavy Falling Weight Deflectometer is 0.2 MN/m² (0.1 MN/m² on the ZFG). The maximum impact force produced by a 15 kg falling weight is double that of the Lightweight Deflectometer at 14.140 kN.


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ZFG-M Mittelschweres Fallgewichtsgerät