Lightweight Deflectometer (LWD)

Lightweight Deflectometers (LWDs) are increasingly being used to determine overall compaction quality of all types of earthworks through their use as a QC/QA field test. LWDs provide a rapid determination of elastic modulus, which is an essential factor in mechanistic design and can be used as an accurate assessment of compaction. An LWD is used for measuring the bearing capacity (deflection) of subgrade/subsoils and unbound base layers, granular layers and backfilling materials, according to ASTM E2835-11. Based on the static plate load test requiring a load vehicle, the LWD provides a simple, fast and repeatable test providing an accurate assessment of compaction parameters. Applications for this non destructive method of testing include bearing capacity and compaction include road construction, pipeline and cable backfill, railway track beds, airport runway/taxiways, dam construction, embankments, foundations and other earthworks.

Humboldt offers two versions of the Lightweight Deflectometers from HMP – deluxe models: the HD-4129.3F (10kg) and the HD-4159.3F (15kg) and basic units: the HD-4130.3F (10kg) and the HD-4149.3F (15kg). Both units are the same mechanism and differ only in the controller used with each one.

The LWD is calibrated at time of manufacturing and comes with a calibration certificate. The calibration is valid for 1 year.

Deluxe Models:
The HD-4129.3F and HD-4159.3F feature a deluxe controller that includes:

• a large, 2.2 x 2.87" (56 x 73mm) colorful display
• light sensor-controlled backlighting that provides the optimum readability even in bright sunlight
• easy menu navigation
• integrated GPS
• integrated WIFI-enabled
• interface for a thermal printer and USB
• help function
• efficient and fast 32-bit processor
• internal memory for up to 1000 tests
• high-performance rechargeable battery

The graphic interface of the deluxe models provides an intuitive menu, which guides the user through the testing procedure and provides real-time test results. Measured data is presented in tabular, as well as curve formats with date. time and GPS location clearly depicted. This data can be exported from the control unit via USB or wirelessly directly into the Cloud or to your PC for archiving and further processing. This allows personnel in any office to have access to data while you are still on site testing. It is also possible to print out results to a small portable printer on site.

Use of the web-based evaluation software: HMPreport, provides the ability to produce professional reports for each measuring point, which can include your logo and contact details. This software allows you to work with your data from the Cloud or your PC. The software also enables you to store the data in a database with easy-to-use search and editing options.

Deluxe Units Include:

• The LWD
• magnetic base plate
• portable printer (USB)
• GPS
• PC Software
• Android App (HD-4129.3F and HD-4159.3F only)

Standard Models:
The HD-4130.3F and HD-4149.3F feature a standard controller that includes:

• a large, 1.50 x 2.68" j(38 x 68mm) graphic black and white display
• integrated GPS
• integrated WIFI-enabled
• interface for a thermal printer and USB
• internal memory for up to 500 tests
• high-performance rechargeable battery

For additional information about the Lightweight Deflectometer, click here.

For more information about Humboldt's compaction uniformity testing solutions, click here.

Visit our geotechnical testing and engineering landing page for more in-depth information.