ASD A100800, User Manual

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ASD Document 600541 Rev. G 53 TerraSpec® User Manual
www.asdi.com Appendix B Reference Information
B.1.12 What are these steps in my data?
Light is brought into the instrument by various combinations of the strands in
the fiber optic cable. Each strand has its own field-of-view (FOV). When the
cable is held close to the sample, each strand views slightly different portions
of the sample. This can result in the stepped data.
Stepping of data is common when the foreoptic has a lens, and less common
when using the bare optics or sampling devices.
B.1.13 What can cause more noise in my data from last time?
Many factors can cause noise in your data from one session to another. Noise
in a measurement is related to the instrument, the signal level, and noise in the
light source. Many times the appearance of noise is actually a decrease in the
strength of the signal, as opposed to an increase in noise.
Under normal operating conditions, noise visible in a spectrum is always the
result of a trade-off between the inherent noise in the system and the signal.
Check how the external fiber optic cable is aligned with the internal cable for
changes in signal through-put.
Figure B-1 Spectrum of fluorescent lights