MTS Series LX Laser Extensometer - Manual (Page 44)

LX Laser Extensometer
Using the Instrument
Operation 44
Measuring Elongation
Do not stare directly into the beam.
Use caution when measuring reflective parts. Do not stare into reflected beam.
1. With the line cord attached and power applied to the unit, turn power switch
to O position. The LCD display will illuminate.
2. Set the laser disable switch to the Laser On position.
3. Set the operating parameters to the desired values using the procedure
previously described. Make certain that the target distance has been set to
the proper value.
4. Attach the retro-reflective targets to the specimen using the desired method
described previously under Target Types and Considerations.
5. Install the specimen to be measured in the test machine. Make certain that
the specimen is located at the proper target distance from the laser
extensometer and that the gauge length of the specimen lies well within the
length of the scan line.
6. Attach oscilloscope to Signal Output jack and check for proper reflection
signal following the procedure described earlier under Monitoring the
Reflection Pulses.
7. Attach a monitoring device (for example, chart recorder, data logger, system
controller, etc.) to the Analog Output jack of the laser extensometer, if
desired. Be certain the monitoring device is properly adjusted to accept the
elongation signal from the laser extensometer.
8. Observe the reading on the LCD display. Press the ZERO key to offset the
reading to zero, if desired, and begin the test. The elongation is displayed on
the LCD display in the chosen system of units. If, for some reason, there is a
problem with the reflection signal (that is, missing or extra reflection pulses)
invalid will appear on the LCD display.
CAUTION