Strain Control

When an extensiometer is attached to the sample, the output of this device may be used to provide feedback for the hydraulic actuator and thus control the strain/ time history of the sample. An Event Detector should be set when using this control mode.
The detector should pass control to POSITION if the sample fails, or stop the machine. If this is not done the servo system will accelerate the actuator piston controlling the grip position, causing it to collide with the end of the cylinder with consequent damage to the machine.


WHEN USED IN STRAIN CONTROL, THE EVENT DETECTOR MUST BE SET TO PASS CONTROL TO POSITION CONTROL WHEN THE SAMPLE FAILS

STRAIN CONTROL SHOULD NOT BE USED IF THE EXPERIMENT IS DESIGNED TO CAUSE SAMPLE FAILURE AS EXTENSIOMETER DAMAGE WILL OCCUR