Measuring
46
4.4.2
Broken Connector
It may also occur that the interrogator adapter sleeve
breaks. In this case, when an optical connector is
inserted it does not get proper alignment and measure
ments are compromised. A broken sleeve will look as
shown in Fig. 4.9.
Fig. 4.9
To solve this problem you should contact HBM
FiberSensing.
4.4.3
Reflective Fiber Ending
It may occur that the interrogator does not find any sen
sor on an array even if connections were performed cor
rectly. One of the reasons may be the excess of reflected
light saturating the detectors.
When a fiber is perfectly cut (Fig. 4.10 on the left), a
large amount of light is reflected right back to the fiber
core in the right direction, heading to the interrogator
detectors. When this occurs, an index matching gel or an
angled termination must be used. If these are unavail
able, the tip of the fiber can be smashed with a metallic
tool. This will destroy the perfect geometry (Fig. 4.10 on
A4249-8.0 HBM: public
FS22 SI