Luna OBR 4600 - Manual (Page 4)

OPTICAL BACKSCATTER REFLECTOMETER TM
(Model OBR 4600)
Extended Range Spot Scan Interrogation 1
www.lunainc.com
3157 State Street | Blacksburg, VA 24060
[email protected]
Support phone: 1.866.586.2682
1 Extended range sensing works best with a low net change in accumulated strain between the unit and the sensing region.
2 Internal wavelength calibration using a NIST-traceable HCN gas cell occurs upon instrument configuration, but may drift with
temperature. Wavelength offset measured at 1550nm. Thermal drift,
ΔT, in degrees Celcius.
3 Based on maximum wavelength range of 3.2 nm.
4 Actual temperature range will be limited by the sensing fiber used.
5 Temperature accuracies are calculated from the wavelength accuracy using the spectral shift of Rayleigh scatter, 1 GHz = 0.8 °C
= 6.
58 µε. [Othonos and K. Kalli, Fiber Bragg Gratings (Artech House, Boston, 1999)].
6 Larger gage lengths may be required to meet noise specifications in the presence of vibration.
PARAMETER SPECIFICATION UNITS
Maximum Range 2,000 meters
Spot Scan Size 80 meters
Maximum Wavelength Range 3.2 nm
Time Per Scan 6.5 seconds
2-pt Spatial Resolution 0.25 mm
Wavelength Accuracy 2 ± 5.0 + 12*ΔT pm
Strain Range 3 ± 1,250 µStrain
Strain Accuracy 2,5 ± 4.1 + 9.9 *ΔT µStrain
Temperature Range 3,4 ± 175 °C
Temperature Accuracy 2,5 ± 0.5 + 1.2 *ΔT °C
Minimum Gage Length 6 3 cm
Minimum Sensor Spacing 0.6 mm
The Extended Range Interrogation
capability is available on the OBR 4600
with purchase of the extended range
mode and spot scan mode. To perform
strain and temperature measurements,
the distributed sensing option is required
in addition to the above. This capability
extends strain and temperature
measurements up to a range of 2 km for
applications located in a benign vibration
environment.
APPLICATIONS
• Evaluating spools of Fiber Bragg
Gratings
• Evaluating optical networks and
devices
• Strain and temperature at a distance