Loadman and Loadman II

Portable Falling Weight Deflectometer


Loadman is a light weight portable device for measurement of deflection caused by a falling weight inside the device. The device is easy to handle and can be used practically on all construction sites and materials under any conditions. It allows measurement of bearing capacity and compaction of construction layers and constructions in places where other commonly used measuring instruments cannot be used owing to their size, or because of the necessity to use a lorry or a van as a weight and/or transportation unit.

Loadman II is an improved version of the original Loadman. It has internal memory for saving results. Saved results can later be saved to a USB memory stick.

We now have two versions of the Loadman II device - a USB only version and the original Bluetooth® enabled version. From the Bluetooth® enabled version measurement results can be transferred wirelessly to a computer or other Bluetooth® enabled device. In addition this model can be connected to a Bluetooth® enabled GPS receiver or Android phone. When connected to a GPS the device saves geolocation data along with measurement results.

All versions of Loadman are powered by rechargeable batteries. Their LCD displays have backlight for enhanced readability.

Measuring principle

The deflection caused by the load of a falling weight is measured by an accelerometer. The acceleration is double integrated and thus the deflection can be calculated. The measuring results are given as the calculated bearing capacity modulus E, the maximum deflection, and the compaction ratio, that is the ratio of the second and further on deflections compared to the first measured deflection (effectiveness of compaction).

Loadman 2
Loadman 2

Range of use

Technically the device can be used on practically all kinds of construction sites to measure bearing capacity and for compaction control on bound, unbound and special layers; for example on roads, streets, brigde sites, house building sites, in trenches, on sports fields (football, baseball, tennis, golf, athletics etc.) as well as for laboratory tests of various kinds of materials.

Technical information

Values in parenthesis are for Loadman II if different from Loadman.

Total weight 16kg
Height 117cm
Diameter of loading plate 132mm, 300mm with an extra plate
Mass of falling weight 10kg
Falling height 80cm
Operating voltage 6V, NiMH batteries
Measuring range 0.1-5mm approx.
Duration of loading / unloading impulse 25-30 ms approx.
Misc. Backlit LCD display and alphanumeric membrane keypad (internal memory for 1000 drops, USB memory stick connector, optionally with Bluetooth®)
What's included Carrying case, 300mm extra plate, battery charger, user manual on an USB memory stick