MTS Series LX Laser Extensometer - Manual (Page 36)

LX Laser Extensometer
Target Types and Considerations
Operation 36
Target Types and Considerations
Basically, targeting the specimen is accomplished by either attaching tape strips
directly to the specimen or by applying the tape strips to tiny spring clips and
attaching these spring clips to the specimen. The spring clip type target is
reusable. Care must be taken to ensure no damage occurs to the retro-reflective
surfaces during use.
Note Some medical researchers have attached reflective tapes with surgical
sutures. Others have used a general purpose adhesive (such as Super
Glue).
The retro-reflectivity of both targets must be approximately the same. This will
be the case as long as the surface of both targets is kept clean, dry, and
undamaged. However, if the surface is damaged or if there is a buildup of foreign
matter, the targets must be replaced. It is advisable to replace both targets as a set
(that is, do not replace individually).
In general, the target width should be kept as small as possible. However, if the
targets are too narrow, problems can arise. These potential problems can be
avoided by observing the minimum recommended target width of 1.02 mm
(0.040 in).