LS User Manual     29
8.0  PERFORMING A TEST
8.1  PERFORMING A TEST
The LS machines can be used to perform tests in two modes, as a stand-alone machine or under 
computer control with NEXYGENPlus™ software.
If the machine is to be used with a computer and NEXYGENPlus™ software, then the NEXYGEN-
Plus™ Software User Manual supplied with the software, should be read in conjunction with this 
manual.  The machine should be connected to the computer with the USB lead supplied.  When the 
machine is on and ready, the computer connected with the lead supplied, and NEXYGENPlus™ run-
ning, connection between the machine and computer is automatic.
If the LS machine is being used in “stand alone” mode, proceed as follows.  The following information 
will also be needed for “setting up” the machine with grips, samples etc.
8.2  TEST PARAMETERS
SAMPLE PREPARATION  The Jog Keys are used to prepare for a test.  The accessories 
      being used will be dependent on the type of test being conducted.
LOAD CELLS    The correct load cell should be tted in the machine for the 
      application being undertaken.  Great care should be taken with 
      these as they are precision measurement devices and can be 
      damaged if used incorrectly.  Please make sure that you have read 
      Section 4.3 carefully before proceeding further. 
GRIPS/ADAPTORS    It is important that grips are tted along the central straining axis of  
      the machine and that no side loads are applied to the load cell as 
      this will affect the accuracy of the load readings.  The grips should 
      be connected to the load cell and the bottom anchor pin or xture 
      using only the pins and parts provided.  Care should be taken not 
      to exceed the load rating of the grips.  It is important to ensure that 
      the grips used are suitable for the material under test.  Any slippage 
      of the material in the grips will affect both load and extension 
   readings.
EXTENSOMETERS    It is important to understand that the extension that the crosshead 
      moves does not give a true reading of the strain in the samples.  If 
      we consider a dumbbell sample for instance, the strain will be 
      different at different positions along the sample and no account is 
      being taken of the take up of slack or bedding in of the grips.  For 
      accurate strain readings we would strongly recommend the use of a  
      LLOYD INSTRUMENTS extensometer, which is suited for the 
   material under test.