ASD Document 600541 Rev. G 55 TerraSpec® User Manual
www.asdi.com Appendix B Reference Information
Step 4 Enable the GPS functionality in the RS
3
application by selecting either:
• GPS->Enable... pull-down menu item.
• Alt+G, E key combination.
Step 5 Refer to the manual of your actual GPS device for further instructions
regarding usage and configuration.
B.1.16 What does a broken fiber mean?
The internal fiber-optic cable is made up of fifty-seven (57) randomly
distributed glass fibers.
• 19 fibers are 100 micron for the VNIR region.
• 19 fibers are 200 micron for the SWIR1 region.
• 19 fibers are 200 micron for the SWIR2 region.
Therefore, a single broken fiber in the internal cable results in a ~5%
reduction in the signal in a given region.
The external fiber-optic cable is made up of forty (44) 200 micron glass
fibers.
Note: Each broken external fiber results in a few percentage loss of response over
the entire range. It is hard to quantify how this affects the response of any
given range, because each time the external cable is connected to the
spectrometer, its alignment with the fibers of the internal cable will most
likely be different.
A few broken fibers is not critical when measuring reflectance, because this is
a ratio. Any noise introduced by the broken fibers in measuring the sample
were also present when measuring the white reference, and therefore cancels
out.
The fibers are protected by a metal spiral inside the black cable casing. If
there are kinks in your cable, the fibers are not necessarily damaged.
However, if your cable has been crunched so severely that you are able to see
the protective metal spiral, the chances are high that the fibers have been
damaged too. Refer to the Fiber Optic Check utility to determine if any fibers
are broken.
The fibers can be damaged by coiling the cable up too tightly. If left in a tight
coil for longer than a week, the fibers are likely to develop longitudinal
fractures that will not be detectable. These fractures in the fiber will cause
light leakage, resulting in a weaker signal. The fiber optic cables should be
stored by placing them loosely within the netting compartment on the
instrument.
WARNING! The fiber cable should never be stored with a bend of less
than a 5" diameter for long periods of time.
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