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Strain gauged column and tester for load transfer verification

EN 12390-4
Main features
  • One cell only, 3000 kN cap., to test either the force accuracy and force transfer
  • Digital tester also connectable to other cells
  • Tester and column can be supplied with official calibration certificate issued by a European   accreditation laboratory
  • Suitable for calibration of Class 1 compression testers
General description
Introduction
The verification of force transfer includes:
  • Accuracy of force indication
  • Self alignement of the upper machine plate
  • Alignement of the upper machine plate
  • Restraint of movement of the upper plate
These verifications can be performed using the 82-E0105/1 strain gauged cell, connected to the 82-P0804/E tester . The processing of data can be automatically performed with a PC with the testing software 82- P0804/E1, E2, E3 and E4 (see accessories).

Description of 82-E0105/1 cell
The device consists of a 3000 kN cap. strain gauged column, 100 mm dia., 200 mm high with hardness and tolerances conforming to standards. The column is gauged with matched temperature compensated electrical resistance strain gauges. Four complete bridges, each centred at one of the ends of a pair of orthogonal diameters half- way up the cylinder are applied. Each bridge consists of two elements measuring axial strain and two measuring circumferential strain.
The column is supplied complete with auxiliary platen and spacers for easy and precise placing of the column either centrally or 6 mm displaced from the centre. The column can also be used as a standard load cell to test the accuracy of force indication.
It has to be used with dedicated strain measuring apparatus as, for example, our model 82-P0804/E.

Description of 82-P0804/E
This tester, when connected to the 82-E0105/1 column, to a PC and printer using the specific software 82-P0804/E1 and 82-P0804/E2, provides completely automatic data acquisition, processing and print of the verification test certificates concerning either the accuracy of force indication or the other force transfer verifications. During operation, acquired data are displayed on the graphic screen and then downloaded by the serial port to PC and printer .The system can also be used directly connected to a simple 24 column serial printer (e.g. our model 82-P0172) or to download the test results for further processing using programs developed by the user.
Supplied complete with carrying case.

Technical specifications

82-E0105/1 strain gauged column
  • Non linearity and hysteresis: ± 0.1% FS
  • Repeatability: 0.03
  • Uncertainty:  0.05%
  • Dimensions: 100 mm diax 200 mm high
  • Weight approx.: 17.5 kg
 
82-P0804/E Force transfer tester
  • Four channels
  • Resolution:
    1/128.000 used with 82-E0105/1 column
    1/256.000 used with load cells
  • Large permanent memory to store data and test results
  • Graphic display 240x128 pixel
  • Bridge impedance: 350 ohm
  • Dimensions: 250x220x150 mm
  • Weight approx.: 2 kg

Ordering info

82-E0105/1 
Strain gauged column/load cell, 3000 kN cap.

82-P0804/E 
Force transfer digital tester

Accessories

82-P0804/E1 
Testing software for the automatic data acquisition and processing of the plate self-alignment and restraint of movement verification (stability) of compression testers.

82-P0804/E2 
Testing software for the automatic data acquisition and processing of force measurements for the calibration verification of compression testers.

82-P0172/M  
24 column serial printer. 110-230 V, 50-60 Hz, 1 ph

82-P0172/1
Serial cable for connection of 82-P0172 printer

82-Q0800/3  
RS 232 serial cable and RS 232 USB adapter

Additional Information

IMPORTANCE OF THE VERIFICATION OF FORCE TRASFER
The result of a compression test on a cube or cylinder specimen is affected to a considerable extent  (up to 30-35%) by a non uniform application of the load on the surface of the sample – this results in an exceptional force being applied to the material and its premature failure. For this reason the calibration certificate for the force measurement instrument mounted on the machine does not guarantee the accuracy of the strength result. Usually a non-uniform application of the load leads to unsatisfactory failures as shown, which cannot be related to a known loss of strength. Since 1983, the BS 1881 specifications have included a testing procedure in addition to the normal calibration test, which verifies the self- alignment of machine components and the restraint on movement of the upper platen using a special strain gauged column (e.g. our model 82-E0105/1) connected to a suitable data acquisition and processing system (e.g. our model 82-P0804/E). This method is also adopted by the EN 12390-4.
All the EN compression testers produced by Controls meet these stringent specifications.