Luna 4600 - Distributed Sensing Measurements

48 Chapter 4
Performing Measurements
4
Figure 4-7. Amplitude of a flat end face reflector. The Blue trace shows the da t a
without the Frequency Domain Window applied. The White trace shows
that
applying the Frequency Domain Window makes the peak details more eviden t.
Distributed Sensing Measurements
If the user purchases this option, s/he can measure five distributed sensing
parameters: spectral shift, spectral shift quality, temperature change, strain, and
temporal shift. The user begins by performing a measurement at ambient state and
storing this measurement in Trace E, the Shift Reference. After a strain or
temperature perturbation is applied to some portion of the fiber under test
(FUT),
a
second measurement is taken and compared to the reference measurement. For
the theoretical background on these measurements, see “Optional Distributed
Sensing Parameters” on page 187.