Light Weight Deflectometer LWD 3032

Light Weight Deflectometer LWD 3032

dual plate system with 300mm & 150mm plates

Other StandardsASTM E2583-07, ASTM E2835-11
Approx. Weight (kg)20
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Call Impact +44 (0)1294 602626

Dynamic plate bearing test system for measuring the bearing capacity of a substrate layer. Weighing approximately 20 kg/44lbs it is highly portable and easily carried around a construction site.

The LWD requires no reference measurements and provides a simple, cost effective alternative to time-consuming and expensive static plate bearing testing.

The LWD is ideal for Quality Assurance / Quality Control on subgrade, sub-base and flexible constructions, on newly built or existing constructions. It can be used to identify the need for further investigation using an FWD and other materials analysis techniques.

Key Benefits


  • Compaction Quality Control and Statistics module providing different compaction criteria to determine percentage compaction according to MNDOT, INDOT, TPF 5-285, Italian ANAS and UK specifications. 
  • Immediate visual summary of information through GIS integration
  • Improved battery life (up to 50 hours idle time per charge).
  • Micro-USB charging port.
  • Ability to perform tests while charging.
  • Enhanced Bluetooth module with higher stability and extended range.
  • Data Collection with your phone using the cross-platform LWD Mobile app on:
    • Android.
    • iOS (Apple).
    • Windows 10.
  • Enhanced Data Collection Mobile App in Lite and Pro mode.
  • Enhanced Data Analysis App in Lite and Pro mode.


Key Operational Features


  • The LWD electronics is interfaced to an iPhone/Android Smart phone & Windows 10 via a wireless Bluetooth connection.
  • The LWD electronics is dust and splash proof (IP56) for safe outdoor use.
  • The drop height is easily and quickly adjusted by a movable release handle.
  • A precision load cell measures the peak value of the impact force of a 10 kg/22lbs, 15 kg/33lbs or 20 kg/44lbs drop weight.
  • The loading plate diameter can quickly and easily be switched between 300 mm/11.8inch and 150mm/5.9inch. The measured data can be used to back-calculate layer moduli and confirm layer thickness.
  • The peak value of the impact force is based on actual measurements from the load cell.
  • The centre deflection is measured through a hole in the loading plate by a highly accurate, seismic transducer (geophone).
  • Optionally, two more deflection transducers can be added.


Key Lite Software Features


  • The data collection software residing in the Smart Phone displays the E-modulus of the surface and the time history graph from both the deflection sensor and the load sensor on the Smart Phone screen, in real time.
  • Relevant information such as name, place and comments can be added to the data file for each measuring point.
  • The E-modulus is calculated and displayed in real time.
  • Both Poisson’s ratio and stress distribution factor parameters may be entered in the user setup.
  • The measurement data can be printed as a report or can be transferred for further processing in spreadsheet or text form.
  • An unregistered version of LWDmod shall be included as part of the LWD, this will allow data to be edited and exported to both MS Word and MS Excel.
  • The software package LWDmod Unlicensed version offers:
    • Imports data into a project database,
    • Editing features.
    • Selected output to EXCEL or Word to a Dynatest standard or UK Interim Advice Note 73.
    • Output of Compaction (requires LWD Pro).


Supplied as:

  • Dual Plate System (150 and 300mm plate)
  • 10kg weight (and 10kg weight buffer)
  • 100mm plate
  • Ribbed rubber mat
  • Load plate centre hole plug
  • Software Included LWD Lite and LWDMod Lite
Additional accessories  & software available - Contact Impact for details & prices
  • Transport box
  • Transport trolley
  • Additional 5kg weight
  • 1st layer buffer (for increased load)
  • 2nd layer buffer (for increased load)
  • LWD Pro APP (allows compaction tests)
  • LWDMod Pro License (allows analysis & plots)