DDS-5F/DDS-5FM

This new microprocessor based advanced model, is a stand-alone machine, driven by a high-solution stepper motor with epicyclical reduction gear with a reduced backlash. Incorporates a pneumatic closed loop system for the automatic application of the axial pressure by a high performance pressure regulator, with the main advantage of eliminating the manual loading of the dead weights.
Excellent quality and high resistance technopolymetric material has been adopted for the carriage of the shear box. It offers excellent resistance to corrosion, wear and tear and is resistant to all chemicals existed in a soil specimen. The carriage is lightweight and easy to clean.

ELECTRONIC
The electronic parts of the system is based on our“ Automax” unit, this is a microprocessor system that reads and processes the force, axial pressure and displacement readings, manages the motor, the pressure valve, the safety systems and the test steps through closed loop systems. It features a front panel in scratchproof poly carbon with a ten keyboard and a large monochromatic graphic display.
ELECTRONIC TRANSDUCERS SUPPLIED WITH THE SYSTEM
The system is supplied complete with:
· +/-5KN capacity load cell, bi-directional type (compression and tension ), nominal sensitivity 3mv/v, accuracy +/-0.15%F.S.
· 5KN capacity load cell, bi-directional type (compression and tension ), nominal sensitivity 3mv/v, accuracy +/-0.15%F.S.
· 12.7mm displacement transducer, accuracy 0.003mm, resolution 0.001mm.
· 25.4mm displacement transducer, same specification as above.
MAIN FEATURE
· Automatic application of preset consolidation steps (No Limit).
· Automatic management of the test with the possibility to failure (the operator only needs to remove the clamping screws of the shear box).
· Sets of heavy and bulky dead weights are not required.
· A balance lever arm maintained horizontal is not required.
· The vertical force is positively applied to the shear box without any friction.
· Easy and immediate set up of the test parameters via the controlling software.
· Possibility to set different speeds and travel *(forward and reverse ) in the residual shear tests.
· Each single step of axial force can be applied:
   -instantaneously (DDS-5F),
   -by means of a linear ramp in a preset time interval.
· Different and independent data recording mode for consolidation and failure.
· Different protocols of data downloading via RS232 serial port.

SHEAR BOX ACCESSORIES
All shear box assemblies are constructed of brass and are designed to contain water that surrounds the specimen. They consist of a square box with a rigid walled round or square hole complete with adapter loading pad, retaining plate, 2 porous stones.

DATA ACQUISITION SYSTEMS
The main interface is composed by 240*128 LCD. The test parameters can be shown and read on the LCD .
Cycle: means times of cyclic shear.
Shear diaplac.(mm):shearing movement.
Rate (mm/min) : shear rate.
Horiz. diaplac.(mm):Horizontal displacement.

SOFTWARE
Acqusition Module.
Standard Consolidation Module.
Standard Shear Module.
Quick Shear Module.
Repeated Shear Module(Option).Post processing function(Option).

TECHNICAL PARAMETERS

Display: monochromatic large digital display (240*128 pixel).
Motor: high accuracy stepper motor with 1/10.000 resolution.
Test velocity: infinitely variable from 0.00001 to 9.99999mm/min (within +/-1%).
Maximum horizontal force: 5KN.
Maximum vertical force: 5kN.
Maximum shear cycles: 9 (forward and reverse ).
Maximum travel: 20mm.
Height of the specimen: 20mm.
Maximum air pressure supply: 10 bar(Only for DDS-5F).
Maximum working air pressure: 9 bar.
Overall dimensions: 820×500×770mm.