ASD A100800, User Manual

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© 2007 ASD Inc. 21 TerraSpec® User Manual
Chapter 4 Fiber Optic Interface
ASD offers a variety of fiber optic cable lengths to interface with the
TerraSpec spectrometer. These fiber optic cables are used for reflectance and
transmittance measurements.
Fiber optic cables should be loosely coiled and stored in the compartments
provided. All accessories should be stored in the designated compartments of
the carrier or in a separate protective case.
4.1 Fiber Optic Cables
Two fiber optic cables are included with the spectrometer: an external cable
and an internal cable (built into the instrument).
• For high resolution spectrometers the internal fiberoptic cable is made up
of thirty-seven (37) randomly distributed, ultra low-OH, silica glass
fibers. Nineteen (19) of these fibers are 100 micron and are distributed to
the VNIR region. The remaining eighteen (18) fibers are 200 micron and
are evenly divided between the two SWIR regions (9 SWIR1 fibers and 9
SWIR2 fibers)
• The external fiber optic cable is made up of forty-four (44) randomly
distributed, ultra low-OH, silica glass fibers that are 200 micron. This
cable has a Numerical Aperture (NA) of 0.22.
The external fiber optic cable length is typically 1.5 meters. Additional
external fiber optic cables can be ordered in a variety of lengths. However, as
the length increases, the cable’s transmission decreases at wavelengths below
400 nm and above 2000 nm.
External fiber optic cables should be coiled and stored in the compartment
provided in the shipping case. All accessories should be stored in the
designated compartment of the case or in a separate protective case.