HBM FS64 User manual

Installation Guide
English
FS64
Tilt Sensor

Hottinger Baldwin Messtechnik GmbH
Im Tiefen See 45
D-64239 Darmstadt
Tel. [phone]
Fax [phone]
[email protected]
www.hbm.com
HBM FiberSensing, S.A.
Optical Business
Rua Vasconcelos Costa, 277
4470-640 Maia
Portugal
Tel. [phone]
Fax [phone]
[email protected]
www.hbm.com/fs
Mat.: 7-2002.4263
DVS: A4263-3.5 HBM: public
05.2015
Sensor Design Version: v2.1
EHottinger Baldwin Messtechnik GmbH.
Subject to modifications.
All product descriptions are for general information only.
They are not to be understood as a guarantee of quality or
durability.

FS64 A4263-3.5 HBM: public 3
English
1 Technical Details 5.........................................
1.1 General Information 5........................................
1.1.1 Overview 5.................................................
1.1.2 Characteristics 5.............................................
1.1.3 Applications 6...............................................
1.1.4 Quality 6...................................................
1.1.5 Accessories 7...............................................
1.2 General Specifications 8......................................
1.2.1 Signal Convention 9..........................................
2 Sensor Installation 10........................................
2.1 List of Materials 10............................................
2.1.1 Tilt Sensor Package 10........................................
2.1.2 Needed Tools 11.............................................
2.2 Parallel Tilt Sensor 12.........................................
2.2.1 Preparing the Surface 12......................................
2.2.2 Placing the Sensor 14.........................................
2.2.3 Unlocking the Sensor 16.......................................
2.2.4 Vertically Aligning 21..........................................
2.2.5 Protecting the Sensor 22.......................................
2.2.6 Locking the Sensor for Transportation 23........................
2.3 Orthogonal and Biaxial Tilt Sensor 23............................
2.3.1 Preparing the Mounting Plate 23................................
2.3.2 Preparing the Surface 25......................................
2.3.3 Placing and Unlocking the Tilt Sensor 28.........................
2.3.4 Vertically Aligning 32..........................................
2.3.5 Protecting the Sensor 32.......................................
2.3.6 Locking the Sensor for Transportation 32........................

4A4263-3.5 HBM: public FS64
3 Sensor Configuration 33.....................................
3.1 Sensor Calibration Sheet 33....................................
3.1.1 General Information 34........................................
3.1.2 Technical Information 34.......................................
3.1.3 Tilt Computation 34...........................................
3.2 Temperature Effect on the Sensor 35............................

Technical Details
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1 Technical Details
1.1 General Information
This installation guide applies to the following products:
Part Number Description
K-FS64-32-11-302 FS64 - Tilt Sensor • Outdoor • FC/APC
K-FS64-32-13-302 FS64 - Tilt Sensor • Outdoor • SC/APC
K-FS64-32-10-302 FS64 - Tilt Sensor • Outdoor • NC
1.1.1 Overview
The FS64 - Tilt Sensor is a Fiber Bragg Grating (FBG)
based sensor, designed to measure small variations of
angle towards the vertical. The sensor uses two FBGs in
an innovative push-pull configuration for effective temper
ature compensation.
1.1.2 Characteristics
: Robustness
Long-term reliability ensured by innovative sensor
design, careful selection of materials and ruggedized
packaging.
: Completely passive
Inherent immunity to all electromagnetic effects (EMI,
RFI, sparks, etc.) and safe operation in hazardous envi
ronments.

Technical Details
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: High multiplexing capability
Connection of a large number of sensors to a single opti
cal fiber, reducing network and installation complexity.
: Remote sensing
Large distance between sensors and interrogator (sev
eral kilometers).
: Compatible with most interrogators
Provided with calibration sheet, allowing easy and accu
rate configuration.
: Self-referenced
Based on the measurement of an absolute parameter -
the Bragg wavelength - independent of power fluctua
tions.
1.1.3 Applications
HBM FiberSensing tilt sensors can be used in a large
range of monitoring applications, such as in slopes and
bridge pillars.
: Civil Engineering
: Geotechnics
1.1.4 Quality
All HBM FiberSensing's processes are strictly controlled
from development to production. Each product is sub
jected to high standard performance and endurance
tests, individually calibrated and checked before ship
ping.

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FS64 A4263-3.5 HBM: public 7
HBM FiberSensing, S.A. concentrates all optical sensing
activity of HBM and is an ISO 9001:2008 certified com
pany.
1.1.5 Accessories
The implementation of complex sensing networks in large
structures is made simpler with HBM FiberSensing
accessories. These include cables especially designed to
resist harsh environments as in civil engineering, not only
during construction, but also during the lifetime of the
structure (humidity, corrosion, etc.).
HBM FiberSensing also provides an orthogonal mounting
plate for one or two sensors allowing transverse or bi-
axial tilt measurements.

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1.2 General Specifications
Sensor
Sensitivity1) 2.0 pm/deg
Measurement range 10 deg (±5 deg)
Resolution2) 0.002 deg
Maximum calib. error 0.05 deg
Optical
Central wavelengths 1500 to 1600 nm
Spectral width (FWHM) < 0.2 nm/FBG
Reflectivity > 65%
Side lobe suppression > 10 dB
Inputs / Outputs
Cable type Ø 3 mm outdoor (armor)
Cable length 2 m each side (±5 cm)
Connectors FC/APC
SC/APC
NC (No Connectors)
Environmental
Operation temperature -20 to 80 ºC
Cross sensitivity < 0.03%/ºC
Settling time 1.5 sec
Mechanical
Materials Stainless steel
Dimensions 220 x 140 x 42.5 mm
Weight 3.3 kg
1) Typical value calculated from the wavelength difference between the two FBGs
2) For 1 pm resolution in wavelength measurement

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1.2.1 Signal Convention
The FS64 - Tilt Sensor signal convention sets negative
angle value for clockwise rotation and positive angle
value for counterclockwise rotation (see Fig. 1.1).
Positive
angle
Fig. 1.1

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2 Sensor Installation
2.1 List of Materials
2.1.1 Tilt Sensor Package
Included Material
Parallel Tilt
Sensor1)
Orthogonal Tilt
Sensor2)
Biaxial Tilt
Sensor3)
Tilt Sensor 112
Calibration Sheet 112
Mounting plate sheet - 2 2
Bracket - 4 4
Umbrako Screw -8xM6 L16mm
2xM6 L25mm
8xM6 L16mm
2xM6 L25mm
Pin - 2xM6 L20mm 2xM6 L20mm
Hexagon Nut - 2xM6 4xM6
Washer - 2xM6 4xM6

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2.1.2 Needed Tools
List of Equipment
Drilling Machine
Interrogator (or equivalent)
List of Material
Parallel Tilt
Sensor1)
Orthogonal Tilt
Sensor2)
Biaxial Tilt
Sensor3)
Hammer 1 1 1
Spanner wrench 10 mm 10 mm
13 mm
10 mm
13 mm
Umbrako wrench -Number 3
Number 5
Number 3
Number 5
Slotted screwdriver L30; D2.8 E0.7
(mm)
L100; D2.8 E0.7
(mm)
L100; D2.8 E0.7
(mm)
D7.0 E1.1 (mm) D7.0 E1.1 (mm) D7.0 E1.1 (mm)
Mechanical anchor Hilti: HSA-R M6
5/-/-(suggested)
Hilti: HSA-R M8
5/-/-(suggested)
Hilti: HSA-R M8
5/-/-(suggested)
Drill bit diameter 6 mm 8 mm 8 mm
1) Parallel Tilt Sensor – only one sensor installed on the existing surface
2) Orthogonal Tilt Sensor – only one sensor installed orthogonally on the existing surface with the
biaxial mounting plate
3) Biaxial Tilt Sensor – two sensors installed on two directions with the biaxial mounting plate

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2.2 Parallel Tilt Sensor
2.2.1 Preparing the Surface
The surface where the sensor is to be installed should be
vertical and regular.
Information
If the sensor wall is not vertical, it will not have the
expected behavior. There is the possibility to design
mounting plates to ensure the right position of the sen
sor.
Fig. 2.1
Make sure of the verticality of the surface and that there
are no major irregularities that could interfere with the
sensor's back side (Fig. 2.1).

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Information
If there are any bumps and/or irregularities when tigh
tening up the sensor, its back can get deformed which
will influence the sensor's behavior.
Afterwards mark two points 20 cm apart and vertically
aligned (Fig. 2.2).
Information
The tilt sensor has a slot to ensure that small corrections
towards the vertical can be performed when the sensor is
being fixed.
Fig. 2.2

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Fig. 2.3
Drill the holes according to the chosen M6 anchors (sug
gested anchor, see section 2.1.2, page 11) with a mini
mum depth of 42 mm.
Verify the screws position with a measuring tape and
then anchor them definitely (Fig. 2.3), tightening them
with a torque of 5Nm.
Remove the nut before proceeding.
2.2.2 Placing the Sensor
Carefully take the tilt sensor out of the transportation box
and place it on the support (Fig. 2.4).
Important
The tilt sensor is a sensitive sensor. Please take extra
care when handling the sensor.

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Fig. 2.4
Fig. 2.5
Place the washer and hexagon nut on both anchors
(Fig. 2.5).
With the help of a bubble level rotate the sensor along
the slot and place the sensor as close to the vertical as
possible (Fig. 2.6). Screw the nuts loosely to allow final
adjustments.

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Fig. 2.6
Information
The tilt sensor has a slot to ensure that small corrections
towards the vertical can be performed when the sensor is
being screwed.
2.2.3 Unlocking the Sensor
Important
The following installation steps should be performed in
accordance with the presented order. Please read the
next introduction carefully before unlocking the sensor.
The FS64 - Tilt Sensor is based on a pendulum mass
that must be fixed for sensor safety during transportation.
For correct usage of the sensor these fixations must be
properly removed. The next installation steps should be

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followed strictly. On the following scheme there is the
order in which locking screws should be removed.
To be unfastened only
(non-removable screw)
To be unfastened only
(non-removable screw)
To be unfastened and
removed (removable screw)
To be unfastened only
(non-removable screw)
To be unfastened only
(non-removable screw)
To be unfastened and
removed (removable screw)
Fig. 2.7
1Any unlocking action should only be performed after
complete fixation of the sensor on the surface.
Throughout the next steps, it is advisable to control both
FBG wavelength changes.
Connect the sensor to an interrogator and control the
Center Wavelengths of the two FBGs so that their differ
ence is as close as possible to the value shown on the
calibration sheet (number 1 on Fig. 2.8).

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Information
The easiest way to perform this control is to configure the
sensor so that the tilt value is measured (equation shown
on number 2 in Fig. 2.8). Nevertheless, if the available
equipment does not have software to perform this auto
matically, it can be done manually by looking directly at
the absolute wavelength values.
Fig. 2.8

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2The mass locking screws should be completely
removed from the sensor.
First, remove the mass locking screws (see number 2 on
Fig. 2.7). There can be some changes on the grating's
wavelengths. The unlocking of the sensor should be
done slowly and by changing sides frequently ensuring
that the wavelengths change is performed in a controlled
way and equally to both FBGs.
Fig. 2.9
Information
Note: Keep the two locking screws for it may be
necessary to lock the sensor for transportation
3The front locking parts should be completely
unscrewed. These will not be removed from the sen
sor.

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Fig. 2.10
Fig. 2.11
Secondly, unscrew the locking screws on the front panel
of the sensor as in Fig. 2.10 (changes in wavelengths
should never be greater than 1 nm). See number 3 on
Fig. 2.7.
4The side locking parts are the last to be unlocked.
Unscrewed them completely. They will not be
removed from the sensor.