• Automatic Computerized Oedometer

Automatic Computerized Oedometer


Standards:
BS 1377:5 | ASTM D2435 | ASTM D3877| ASTM D4546 | AASHTO T216 | NF P94-090-1 | NF P94-091 | UNE 103-405 | UNE 103-602
 

The oedometer consolidation test is used to determine the rate and magnitude of consolidation of a soil specimen restrained laterally and subjected to a number of successive increments of vertical load.

The ACE (Automatic Computerized oedometer) consists of a small and compact load frame housing two coaxial pneumatic cylinders: the smaller one for low loads and the other for higher loads, with automatic switch-ing from one to the other when needed. There are two analogue channels: one for the displacement transducer and the other for the load cell with closed-loop feedback, which controls application of the required pressure using a high precision pneumatic servo-actuator. Test parameters are pre-programmed and saved in the ACE software by the opera-tor, including the test end, which Technical specifications - Maximum vertical force: 15 kN - 30 kN available on request - Load cell capacity: 15 kN - Displacement transducer: 10 mm maximum travel - Maximum air pressure supply: 10 bar. (If the air pressure source is not available in the laboratory, our air compressor model 86-D2015, 50 l capacity may be used. - Specimen size: from 50.47 to 112.80 mm diameter using our consolidation cells. See Accessories. Software: can control up to 60 ACE units (not included, see Accessories) - PC connection: LAN cable (included) - Measurement accuracy: better than 1% - Overall dimensions: 280 x 300 x 600mm (w x dx h) - Weight approx.: 25 kg (approx.) can be programmed on a time or increment basis. The software can control up to 60 ACE units from a single PC, giving the operator the choice of controlling single or multiple units. Once the software is installed (mandatory) with the first ACE unit, it is possible to extend the control of further units just by enabling the communication without additional interventions and costs. An IP address is given to each unit for the LAN communication: system modularity is ensured for subsequent integra-tions. 

Detail of load cell and displacement transducer

 

ACE software allows to set up, save and recall different load/unload sequences: for each of them applied pressure steps, recording mode, time of application, swelling control and secondary consolidation rate limit can be defined by the user. Besides the traditional time limit control for transition from one step of pressure to another, further automatic controls are included in the software with great advantage to the users, as:

  • Swelling control: if the specimen under test tends to expand, a swelling limit can be pre-set: in case the pre set limit is exceeded, the system will automatically skip to the next loading step.
  • Secondary consolidation rate control: the system will automatically skip to next loading step if the secondary consolidation rate is lower than a pre-set limit.  

Test results are recorded and displayed in real time and calcu-lations are performed automati-cally. Test data can be processed using the proper Geo-Analysis Templates conforming to BS or ASTM Standards. The frame can accept all standard consolidation cells, from 50.47 to 112.80mm diameter. Consolidation cells, Geo-Analysis templates and test software are not included. See Accessories. PC is not included.

 

Main features Technical specifications
  • Fully automatic PC-controlled test execution
  • Three conditions for the automatic switch to the next step are available: time, swelling, rate of secondary consolidation.
  • Testing can continue 24 hours a day, 7 days a week without interruption giving greater throughput of tests with a considerable cost decrease
  • Automated loading eliminates negative factors such as operator error and manual handling of dead weights
  • 15 kN maximum loading capacity, 10 mm travel displacement transducer
  • Real-time data and graph display
  • Single ACE software installation controls up to 60 units
  • Test management software supplied including calibration facility
  • High speed LAN network communication 
  • Maximum vertical force: 15 kN - 30 kN available on request
  • Load cell capacity: 15 kN
  • Displacement transducer: 10 mm maximum travel
  • Maximum air pressure supply: 10 bar. (If the air pressure source is not available in the laboratory, our air compressor model 86-D2015, 50 l capacity may be used.
  • Specimen size: from 50.47 to 112.80 mm diameter using our consolidation cells. See Accessories. 
  • Software: can control up to 60 ACE units (not included, see Accessories)
  • PC connection: LAN cable (included)
  • Measurement accuracy: better than 1%
  • Overall dimensions: 280 x 300 x 600mm (w x dx h) 
  • Weight approx.: 25 kg (approx.)
  • 110-240 V, 50-60 Hz, 1 ph. 

 

 

 

Accessories
Test Software 26-WF3120/SOF ACE automatic computerized oedometer
test software
Consolidation cells   (see below)
Permeability accessory (optional) 26-WF0338/B Permeability attachment with 50 ml
graduated burette.
Geo-Analysis templates
for data processing
30-WF6016/T1 Consolidation Geo-Analysis template
conforming to BS1377:5 Standard
30-WF6016/T8 Consolidation Geo-Analysis template
conforming to ASTM D2435 Standard
Hub 26-WF4645 LAN Hub with 8 ports for Wykeham
Farrance devices. LAN cable from hub to PC
is included.
Alimentation air    

 

 

Consolidation cells:

Code 26- Specimen
Dimensions
(dxh) mm
Specimen
area cm2
Cell dim.
(dxh) mm
Weight
(kg)
Calibration
disc, code
26-
Upper
porous disc
code 26-
Lower
porous disc
code 26-
Cutting
ring
code 26-
26-WF0320 50.47 x 20 20 00 139x14 1.3 WF0320/9 WF0320/4 WF0325/10 WF0320/3
26-WF0321 63.50 x 20 31.67 139x14 1.3 WF0321/9 WF0321/4 WF0326/10 WF0321/3
26-WF0325 71.40 x 20 40.00 139x14 1.3 WF0325/9 WF0325/4 WF0325/10 WF0325/3
26-WF0326 75.00 x 20 44.16 139x14 1.3 WF0326/9 WF0326/4 WF0326/10 WF0326/3
26-WF0335 112.80 x 25 100.00 200x74 3.0 WF0335/9 WF0335/4 WF0335/10 WF0335/3

 

 

 

Software
ACE software operates as interface for all testing processes: the possibility to pre-set all test conditions and let each oedometer unit to work independently and to perform the whole test automatically is the great advantage of ACE testing system, ensured by the dedicated software developed by the geotechnical experts.

Modularity concept: up to 60 ACE units can be connected to the same PC via LAN and controlled by the same software 26-WF3120/SOF.

Calibration and verification facilities for force and displacement transducers are included in the software. Txt files are automatically generated for calibration reports. Each system is factory calibrated but verifications have to be ensured by the users at least once a year. The screenshot above shows an example of test sequences setting, where swelling monitoring and control option is activated. For each step, test data are displayed in real time and recorded according to the pre-set logging mode. Testing unit status is continuously displayed and time scale can be switched immediately from linear to logarithmic and square root.