The principals of operation of the PANDA 2 and the Automatic Hammer are covered:

PANDA 2  Dynamic Cone Penetrometer The PANDA 2 is a light-weight (total weight of equipment 20kg) dynamic cone penetrometer (DCP), which uses variable energy and can be operated by one man to test soils in almost any location to a depth of 6 metres. The test is carried out by driving a cone (2, 4 or 10cm2) on the end of a set of rods using a fixed weight hammer. For each blow of the hammer, the microprocessor records the speed of impact of the hammer and hence calculates the amount of energy used. An acceleromerter on the head of the tool measures the speed of inpact of the hammer while, the depth of penetration is measured by a retractable tape. The microprocessor uses the depth of penetration and energy for each blow of the hammer to calculate the dynamic cone resistance (qd) using the Dutch Formula (Cassan M. 1988) and records and displays the values for qd along with the corresponding depth. The Dutch formula is shown in the figure. A is the area of the cone M is the weight of the striking mass P is the weight of the struck mass V is the speed of impact (of the hammer)

Studies have proved the reliability of the results obtained compared with standard in situ tests.
The PANDA 2 is supplied with 10 rods, each 50 cm long.

Following the on-site tests, all data recorded by the PANDA micro-processor (depth and cone resistance q_d) are transferred to a PC using the specially designed user friendly PANDA WINDOWS software package.An extensive series of pre-calibration tests on standard backfill materials have been conducted to establish reference q_d profiles for different compaction levels and soil classifications, like USCS. The related pre-calibrated reference curves for an extensive database of soils and materials are available to choose from in the PANDA software database. After entering the features of the trench, the type of the filling material used and the compaction quality required; the Panda Windows Software will plot lines reference and failure, which when compared to the test data, allow an assessment of the quality of the work to be made. The figure below illustrates typical compaction quality control test PANDA penetrograms obtained and the reference curves established under compaction levels corresponding to 92% and 95% of the maximum dry density obtained from a standard Proctor test.

AUTOMATIC HAMMER

For deep or repetitive tests, an automatic hammer alternative is available as an alternative to using the 1.7kg hammer. The Automatic Hammer can also be operated by one person.

During a soil investigation with the PANDA (French Standard XP P 94-105), you can switch from manual hammering to automatic hammering. A 20kg hammer is used over the PANDA’s head with 3 different levels of hammering (low, medium and high). The Automatic Hammer is safe, easy to use and needs a minimum amount of maintenance.The automatic hammer uses a 20kg hammer which is dropped from one of three heights: Drop Height (cm)  Pressure Exerted (J) Low  20  39 Medium  46  90 High  64  125

The PANDA 2 measures the energy exerted to the system with each blow so the operator doesn’t need to tell anything to the PANDA 2. The energy is measured automatically as we have always the same weight. You have to adjust the PANDA 2 calculator if you work with the hammer manually (1.7kg) or with the automatic hammer (20kg).